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97 steering pump on the ground 1h/less! with pics

30K views 47 replies 15 participants last post by  Mmusicman 
#1 ·
i had mine out in an hour and a half, but then i also took pics. here's how.
the tools.
specialty tools: steering pully puller, compressor, air chisle.
breaker bar, 3/8"adaptor
1/4"drive sockets, 8mm,10mm,13mm, extentions.
3/8"drive sockets, 10mm,13mm,14mm deep, extentions. i like spark plug ratchet.
wrenches, 10mm,13mm,14mm,16mm, 20mm/13/16. 20mm is really tight and you will find 13/16 is better.
panel popper
large flathead screwdriver
foam ear plug
channel lock pliers, regular pliers
2 bungi cords

step 1
unplug mas/vas from corragated intake tube
using 8mm with ratchet, loosen the intake clamp from the intake elbo. using the panel popper, pry up on filter box from each side, disconnect cold air tube and resinator. give a good pull upwards to seperate the filter box from the fan shroud. twist the whole box and intake tube untill the intake tube gives, then just pull back. the whole intake comes out.
step 2
using 10mm 1/4" ratchet with 8" of extention(s) pull 4 coarse thread bolts from sides of fan shroud, then 3 bolts on the top. pull up on the passenger side of the shroud untill it clears the rad cap. you will have to battle with the throttle cable and upper rad hose, but don't remove the rad hose. best way is to get your right arm under both and allow shroud top to pull up from passenger side. you will want to compress the top to clear the master cylinder.
step 3
fan removal and belt removal. get out the air chisle. you don't need much but there is a method to using. chisle to the left and carefully engrave the left side of a flat on the fan nut. as soon as the fan nut moves, it's enough. take channel lock pliers and loosen 1 full turn, then just spin the fan off by hand... unless the clutch is worn, then you have to spin with your hand.then pull out the lower fan shroud from passenger side. there are 3 tabs that will need to be released. using a breaker bar with 3/8" adaptor with 3/8" extention. release pressure from the tentioner and remove belt.
step 4
seperate the a/c pump and support a/c. remove 4 13mm bolts from the top of a/c pump. there is a short, black bracket which is held in by one of the a/c bolts and a 10mm bolt holding the oil add tube. remove bracket but not the oil add tube, just remove the 10mm bolt. wrap a bungi cord around the a/c pully, then stretch bungi up to hood pin. the hood support will hold. you only want to support the a/c pump about 1"
step 5
remove the pump and bracket. you don't need to remove the pully at this point, start with the hard nut first, it's located on the side of the block just behind the pump. it's easy to remove from the top, it's blind though. this is where i like the spark plug ratchet. feel around a bit, you will find it, you just can't see it. get a deep 14mm socket and fit over the nut and just crack it loose, don't remove cause you will forget where it goes. just loose. then remove 3 14mm bolts from the front and one nut. the nut is a support stud and if you remove cause the nut is bound up, place the stud back and thread it back in.
step 6
using a normal pair of pliers, pull the hose clamp down to the middle of the resivior return hose, use of a panel popper makes quick work of seperating this hose. make sure to have a small catch pan under the res hose. remove 2 10mm bolts from power steering resivior. tip the exsess out into the catch pan. using a foam ear plug, fit into resivior return hole and you will want it almost all the way in... don't worry, it will expand out enough so you can retreve it after. twist the resivior counterclock wise and shove it down towards the pump/bracket, twisting the hose around the brake booster. you will need to move the a/c pump sideways for the res to clear, then making sure the lid is on tight and the ear plug is still secure, flop it down onto the steering links below.
step 7
there are 3 connections still left. grab the bottom of the power steering pully with right hand hand and lift a/c pump with left hand and forcefully wiggle the steering pump bracket off. be carefull here cause the electrical connection is very short. remove power steering bracket and let it gently flop onto the steering links below. that exposes the bottom return line connection, the high pressure line and the electrical plug. the high pressure line is 16mm wrench. have an oil pan under the van to catch all the powersteering fluid.
remove steering pump pully and bracket as an assembly and place it in drain pan. remove ear plug.
step 8
using a powersteering pully puller tool to remove the pully on the bench. if you don't know how to use the puller tool, stop and get the info cause you WILL strip the threads on the tool as well as on the pump. there are 3 13mm bolts under the pully and 2 nuts holding a rear bracket to the back of the pump housing. that's it.
you can order a new pump with a new housing, which is pricy. or if you have just a new pump it will come with the nessasary o-rings. plan on a new o-ring for the high pressure line also.
the electrical potion is a bit complex and will require you to sit down and take your time. the metal is soft alluminum. i have a pic of all it's components in an exploded view to show the order of removal, cause at this point... i can't explain. i don't even know what to call this part(s).

hope this helps speed up the process of a dificult removal. as you will see, there are many skipped procedures that i find makes a bigger mess and overcomplicates the whole job.

reinstallation: lay the pump/bracket assembly on it's side. attatch the high pressure line first and remember to put the line on the inside of lower bracket and tighten with the line twisted so that when you install the assembly, the line will straighten on it's own. cause it's a real pain to tighten this line from the bottom. then feed the resivior back through to is final resting point. install assembly onto stud, it will click one time, then you can push it into place making sure the rear fork bracket installs onto stud. put bracket housing bolts (14mm) back in and tighten down, do not forget to tighten the nut on the back. the rest is simpley the reverse of removal.
 
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#27 ·
removing the outer electrical portion allows you to get a deep socket over that for removal, or you can use a wrench.

In regards to the position, the only thing that matters is making sure you plug it in...the electrical connector position shouldn't really matter from what I noticed when doing mine.
 
#28 ·
Thanks Chevymaher and Redfury. So now I am stuck getting the sending post (not sure what to call it) off the old pump and onto the new. The picture is not clear but I rounded off the corners of the hex with what I thought was the correct deep well socket. I am thinking the only way that stud is coming off is with vise grips which will destroy it. I hope you can buy a new one?? G.B.
 
#29 ·
I thought I read here that there is a replacement part from GM to replace the assist.....should almost have a thread that identifies all the replacement parts by GM part number that are harder to figure out or find.
 
#30 ·
vise grips are you solution imo. compress the grips several times adjusting an 8th of a turn ( or less ) simultaneously. to get the teeth to bite better, you should apply top force while loosening to prevent marring the nut further. slowly wiggle the connection back and forth and readjust before loosening, this ensures maximum bite. first tighten just a crack and then loosen, this compresses the rubber O-ring, breaks corrosion and allows air to pass through the corrosion preventing damage to the threads. tighten back up, and loosen. if you feel the grips loosen, readjust the grips and continue. if using channel lock pliers, while wearing gloves, apply top force with your thumb. in both cases, don't try and make multiple teeth marks. the secret to vise grips imo is to multiply surface contact and patience. if you're careful, you might save the nut.
if that doesn't work, a small hammer and a chisel will be left. in this case I would try drilling a small divet in the nut flange and use a small punch. do not drill through.
the reason you stripped the nut is because there was more play in the connection or your socket taper is too deep for the thin fastener. some times you have to get selective with your wrenches. often times I find that switching between sae and metric gets me the best fit. sometimes I use a hammer to tap the socket onto the nut. not all tools are created equal, so not all brands are going to spec on... all the time.
 
#31 ·
cowboydan said:
vise grips are you solution imo. compress the grips several times adjusting an 8th of a turn ( or less ) simultaneously. to get the teeth to bite better, you should apply top force while loosening to prevent marring the nut further. slowly wiggle the connection back and forth and readjust before loosening, this ensures maximum bite. first tighten just a crack and then loosen, this compresses the rubber O-ring, breaks corrosion and allows air to pass through the corrosion preventing damage to the threads. tighten back up, and loosen. if you feel the grips loosen, readjust the grips and continue. if using channel lock pliers, while wearing gloves, apply top force with your thumb. in both cases, don't try and make multiple teeth marks. the secret to vise grips imo is to multiply surface contact and patience. if you're careful, you might save the nut.
if that doesn't work, a small hammer and a chisel will be left. in this case I would try drilling a small divet in the nut flange and use a small punch. do not drill through.
the reason you stripped the nut is because there was more play in the connection or your socket taper is too deep for the thin fastener. some times you have to get selective with your wrenches. often times I find that switching between sae and metric gets me the best fit. sometimes I use a hammer to tap the socket onto the nut. not all tools are created equal, so not all brands are going to spec on... all the time.
Thanks Cowboydan for the tips. I finally figured out what I am dealing with, the EVO variable speed sensor. I am a little slow sometimes :). If all else fails, I talked to my local Chevy dealer and they confirmed that you can't by a new EVO sensor. They have a new EVO sensor eliminator kit in stock at my discounted price of $60. I searched the net and could not find new EVO sensors for sale anywhere. Thanks again to all for your help. G.B.
 
#32 ·
Gone Blue said:
...I finally figured out what I am dealing with, the EVO variable speed sensor. I am a little slow sometimes :). If all else fails, I talked to my local Chevy dealer and they confirmed that you can't by a new EVO sensor. They have a new EVO sensor eliminator kit in stock at my discounted price of $60. I searched the net and could not find new EVO sensors for sale anywhere. Thanks again to all for your help. G.B.
When I called the GM dealer about this also very recently, they told me it was called an actuator (which is the opposite of a sensor - an electromagnetic that moves a valve in this case). The part number of the EVO valve/solenoid/actuator was 26069030 but has not been available since 2006. It was replaced by a kit (P/N 26009895), that is also called a "fitting" that retails for $27 at GM dealers. I think you probably have either been quoted with some overnight-shipping charges or possibly they have misidentified part. This EVO actuator was only on the 1997 and 1998 Astros and Safaris. The replacement fitting makes the actuator unnecessary. I suppose it also eliminates the variable-effort feature, which is not necessary for safe control of the vehicle. I don't know if this feature was removed for the 99 & later models or if it was just implemented some other way.

Good luck. You're not the only one working on their Astro power steering :pray:
 
#33 ·
97AstroLT said:
Gone Blue said:
...I finally figured out what I am dealing with, the EVO variable speed sensor. I am a little slow sometimes :). If all else fails, I talked to my local Chevy dealer and they confirmed that you can't by a new EVO sensor. They have a new EVO sensor eliminator kit in stock at my discounted price of $60. I searched the net and could not find new EVO sensors for sale anywhere. Thanks again to all for your help. G.B.
When I called the GM dealer about this also very recently, they told me it was called an actuator (which is the opposite of a sensor - an electromagnetic that moves a valve in this case). The part number of the EVO valve/solenoid/actuator was 26069030 but has not been available since 2006. It was replaced by a kit (P/N 26009895), that is also called a "fitting" that retails for $27 at GM dealers. I think you probably have either been quoted with some overnight-shipping charges or possibly they have misidentified part. This EVO actuator was only on the 1997 and 1998 Astros and Safaris. The replacement fitting makes the actuator unnecessary. I suppose it also eliminates the variable-effort feature, which is not necessary for safe control of the vehicle. I don't know if this feature was removed for the 99 & later models or if it was just implemented some other way.

Good luck. You're not the only one working on their Astro power steering :pray:
Interesting, thanks for clarification and part number for EVO actuator. I will discuss your part number above for the fitting with my favorite Chevy parts guy. I have a 98 Astro. Thanks again, G.B.
 
#34 ·
I meant to write "electromagnet" above, not "electromagnetic". An actuator enables the computer to have a physical effect (so sometimes it's called an "output"). I have the GM service manuals for the '97 and I read the part about the EVO. The computer causes a controlled amount of current to go through the electromagnet in such as way that as the vehicle speed is high (over about 40 mph, based on something I read) the valve somehow reduces the flow to the steering gear compared to the flow allowed at low speeds. The manual doesn't have a good enough diagram to illustrate how it moves to accomplish this. But it does say that the current is pulse-width modulated, meaning that the way the desired effect is achieved involves varying the length of time that the electromagnet energized by pulses of electricity (current). I happen to be an electrical engineer and modulation schemes were part of some of the classes (at the time I went though at least - the required classes tend to change over time).

Looking at the picture of your AC Delco pump, it's not real clear to me how it is to be used for the '97-'98 models. I wonder if they have a tech support line that would put you in touch with someone that could answer that question. It seems that hex nut would have to come off for you to put the bracket and EVO actuator on their pump. At least that nut would have to come off or be covered by the bracket if it is supposed to end up looking the same as the
'97 OEM pump.
 
#35 ·
The output has a hydraulic valving that is moved by the EVO unit restricting the output of the pump. Interesting to read that it was only on 2 model years though. I don't understand why they put it in in the first place, or why they took it out. Seems like somebody at GM decided they wanted to try something and it didn't work as intended.
 
#36 ·
redfury said:
The output has a hydraulic valving that is moved by the EVO unit restricting the output of the pump. Interesting to read that it was only on 2 model years though. I don't understand why they put it in in the first place, or why they took it out. Seems like somebody at GM decided they wanted to try something and it didn't work as intended.
I think you're right - they dropped it for some reason. Reading the service manual section on this a bit more, this EVO was pretty complex: a separate computer module behind the instrument panel to the right of the radio, a sensor to detect steering wheel position (and about that it says the sensor detects "evasive maneuvers" so it may just detect quick changes to position, not raw position), then of course, the EVO actuator on the pump. This is a logical target for cost-cutting and reliability enhancement. And after noticing the part about it being supposed to detect and reduce power assist to "evasive maneuvers" when at high speed, it's possible this is only a safety feature that never benefits a driver who knows not to overcorrect when responding to a hazard.

Another surprise was that the service manual says that EVO equipped vehicles have a special pressure line with a 1-way valve in it. The purpose of that is to prevent a "kick-back" effect from the EVO when the vehicle hits bumps in the road (pot-holes and railroad track are examples). I know neither of my pressure lines have a 1-way valve in them!

I'm posting more details about my recent steering issue on another thread (http://www.astrosafari.com/viewtopic.php?f=46&t=27202&p=280786#p280786), but the EVO system is now my prime suspect.
 
#37 ·
cowboydan said:
seperate the a/c pump and support a/c. remove 4 13mm bolts from the top of a/c pump. there is a short, black bracket which is held in by one of the a/c bolts and a 10mm bolt holding the oil add tube. remove bracket but not the oil add tube, just remove the 10mm bolt. wrap a bungi cord around the a/c pully, then stretch bungi up to hood pin. the hood support will hold. you only want to support the a/c pump about 1"
I realize this is an old thread but I am curious about the method used.

Is there a typo here? Should a/c references be p/s references as in power steering? I don't get why it is necessary to remove the a/c 'pump' which is non-existent. There is an a/c compressor and a p/s pump but not an a/c pump.

I am not being picky, I just want to confirm that removing the a/c compressor is not necessary. I can pretty well derive the meaning from the description but would appreciate confirmation.

Also, the description could fit the a/c compressor (2001 Safari) removal since there are 4 bolts on top and an oil add tune nearby that I think has to be removed for a/c compressor removal. There is also a short bracket attached to one a/c compressor mounting bolt.

It does not make sense at this point since the p/s pump is well below the a/c compressor.
 
#40 ·
I assumed Cowboydan meant the A/C compressor since a compressor is a type of pump. My van is on a drive at the moment but I think A/C compressor mounts on the same large metal bracket as the P/S pump. The P/S pump attaches to the lower part of it and there are 4 holes for bolts on top of the bracket where I assume the compressor goes (I do have a spare bracket I could look at quickly - which I'll probably never use now, but I pulled it at a salvage yard in case my bracket was broken when I worked on my steering system last year). I'm pretty sure it's one of those 4 upper bolt holes where the tube for adding engine oil attached, which would is also consistent with Cowboydan's comment about the oil add tube. The bolt that held my add oil tube had stripped out and I had been using a small bungee cord up to the steering fluid reservoir to hold it in place for a while and I wanted to fix that when working on my steering system. Instead of replacing the bracket I ended up cleaning up the threads in oil tube bolt hole with a tap and getting a longer bolt in order to also reach deeper threads, and that made it solid again. Replacing that while metal bracket would been a big job. Pulling it at the salvage yard wasn't bad because so much had already been removed.
 
#42 ·
Unfortunately I can't answer your question as mine have never had it, but I don't think it would make that much of a difference, and there is a reason it was only on 2years and not the later years.
 
#43 ·
Sailing_Faith said:
I have a pump to change today, my 97 has been progressively leaking more and more...

Has anyone noticed a difference after they eliminated the EVO with the kit?

Is there any real change in steering effort?
I never noticed a difference - mine had EVO then I got it removed in the process of trying to eliminate issues with the steering system (after each of 3 steering gear replacements the system was not able to be bled of air successfully). I had the shop manual and remember reading about the EVO system there. Its purpose was for safety in order to prevent or reduce the likelihood that the driver would over-correct during a high-speed maneuver, which most likely would roll the vehicle. I'm pretty sure that under anything but a very-quick turn at high speed (which would be very dangerous) you would not notice a difference. I know I never noticed a difference.

By the way, removing the EVO didn't eliminate the problem with air getting in to the system. That problem was finally resolved when I found a used steering gear in a working '96 Astro that had been turned in for recycling. I removed it with help of a salvage yard mechanic. A lot of the fluid remained in it. Back at home, with used P/S hoses I had, I tested it before putting it in the vehicle. In exactly the same way and using the same used hoses, after I pulled it out of the vehicle, I tested the almost-new aftermarket gear I had received under warrantee service. The recommended bleeding procedure involving 20 to 40 simulated turns worked as expected for the used gear (bubbles went away before 40 turns), but bubbles did not stop coming from the gear after any number of simulated turns with the aftermarket steering gear under test. The used gear fixed the problem in the van also - the bubbles in fluid and hiss finally ceased once and for all. I concluded there was probably something being done wrong at more than one facility that rebuilds the steering gears. If you're interested, the saga of my steering problem is recorded on this site (viewtopic.php?f=46&t=27202). I don't wish a problem like it upon anyone! It took so long to fix as a DIY mechanic that in the mean time we bought another minivan when a deal came along. I just sold that 97 Astro, which I have hope still has many miles left in it for the new owner. It was at 187K.
 
#44 ·
97AstroLT said:
My van is on a drive at the moment but I think A/C compressor mounts on the same large metal bracket as the P/S pump. The P/S pump attaches to the lower part of it and there are 4 holes for bolts on top of the bracket where I assume the compressor goes
Long time getting back but I see what you mean now. I inspected the metal bracket (on a 2001 GMC Safari cargo van) while I had the compressor out and it does seem to be bolted to the engine. I made a mental note to hit the bolts with PB Blaster in case I have to remove it sometime.

The compressor does bolt to the top of the bracket.

I had better luck than you with the oil filler pipe bracket bolt. I also discovered that the oil filler pipe just pushes into the engine block and can be pulled completely from the dog house end once the bracket retaining bolt is removed from the foot of the bracket you mentioned.

While I had it all out I pulled the EGR valve and squirted it with WD40. Freed it completely. Hoping for better idle now.
 
#45 ·
Is there a how to on just removing the high pressure line? I am under the van with it on a lift and I have no idea how you're supposed to get access to the fitting on the back of the pump.
 
#47 ·
ADDvanced said:
Is there a how to on just removing the high pressure line? I am under the van with it on a lift and I have no idea how you're supposed to get access to the fitting on the back of the pump.
Hey man, you only have to post your question once and not in multiple threads, I deleted the other one.

Most just look at the active topics list https://www.astrosafari.com/search.php? ... ive_topics so they will see the new posts.
 
#48 ·
ADDvanced said:
Is there a how to on just removing the high pressure line? I am under the van with it on a lift and I have no idea how you're supposed to get access to the fitting on the back of the pump.
What is so simple with the RWD is near impossible with the AWD. I found it easier to remove the bolts on the master bracket first, to give you some "wiggle room". You may need to remove the 4 bolts in the a/c compressor, but don't disconnect it, just hang it up with a bungee. There is also a bracket on the back of the PS pump which might be a bear to remove.. I was able to remove mine thought the fender well.. and did not reinstall it. I think I also pulled the bolts in the idler arms for a little bit more wiggle room too.

AstroWill said:
..I deleted the other one..
:mrgreen:
 
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