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Discussion Starter · #1 · (Edited)
Hi all, looking for some advice on what could be going on to cause my hydroboost and power steering system to fail twice - once it led to grinding when turning the wheel, had both parts replaced, then it quit suddenly on the highway a month later. Curious any thoughts. I share the full story below for background information. Thanks for taking the time to read and/or share your thoughts.

2002 AWD ~146k miles
Bought in southeast, from wyoming, converted to camper van. lived out of it in the desert for a few months before heading to the mountains. Put about ~10k miles on it since I bought it.
When I got to Colorado, I started noticing power steering issues after driving through the mountains. Then a friend borrowed the car and put some basic O'Reilley's power steering fluid in it (didn't tell me until after the fact). When I got back to the van, the issues seemed way worse: grinding/tightness when turning the wheel without gas, loud noises when making tight turns, etc.
Took it to a Firestone in Durango, CO. They said the hydroboost system was leaking so they replaced it. While doing so, they discovered there was a mystery fluid in there that also damaged the power steering pump so they replaced that too.

Car drove great for a month then....

yesterday as I was driving on I-25 through Denver in rush hour traffic and accelerating to merge it suddenly jolted and felt as though I lost most of my power. I immediately pulled over, then decided I should get off the highway. drove/slow rolled the car off the highway. It felt like the power would come and go. Eventually I got into a parking lot and checked the fluids. All was good but the coolant was low and the transmission fluid was high. Was going to drive it to a shop but when I backed out of the parking spot the car just wouldn't drive any more - no matter how much gas I gave it, it wouldn't budge. It took 3 people to push it back into the parking spot. It felt like the brake system was locked up, but I wasn't on the breaks and I didn't have the e-brake on.

Got it towed to a nearby mechanic who originally thought it was the front differential but then said the hydroboost system was bad. It's covered under warranty/insurance from the previous repair. He just called and said the power steering is also bad.

I'm writing because I'm curious (and worried) that there is something else going on in the vehicle that is causing this systems or these parts to fail. I live in this van full time and drive to remote places for work/play, so I worry about it shitting the bed again in the middle of no where. I plan to take it to a dealership to get it checked out once I get it back from the mechanic where it is now, but I see so many wonderful posts and comments on this forum I wanted to see if anywhere here would have any ideas on what else could be going on.

Thanks all so much for taking the time to read my sad saga and offering any insight you might have.
 

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If they failed to flush the system to get the metal particles out of it, then it will destroy more parts. I had a Silverado that I replaced the pump and 2 months later it went bad again and the parts store guy asked me if I flushed the system. So did a little research, and it should be done any time you replace a large component.
 

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I agree with Mark about flushing the system…. Good idea.

as for the fluid causing the problem…. Not likely. GM recommends power steering fluid. Some run ATF and report no problems. I don’t think the fluid caused the problem.

That said, I notice that often hydroboost “problems” are detected by shops when no problem existed for the owner…. It’s like the system is unknown to them so it is automatically suspect.
There are many ways to go wrong installing a hydroboost. The rod length varies…. Lines leak that did not leak before.

Whenever the system is opened it MUST be bleed…. A lot. The front of the van unloaded (on lift or jacks) must be turned lock to lock 10 times…. 20 times to be safe.

If there is air in the system it will cause problems.

Now, after all I just wrote…. The problem of “grinding” while steering sounds like your idlers are worn and your center link is hitting the harmonic balancer….

Super common problem on AWD vans…. Something a competent mechanic would have found immediately instead of changing a bunch of unrelated parts.
 

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2002 Astro LT RWD
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Was going to drive it to a shop but when I backed out of the parking spot the car just wouldn't drive any more - no matter how much gas I gave it, it wouldn't budge. It took 3 people to push it back into the parking spot. It felt like the brake system was locked up, but I wasn't on the breaks and I didn't have the e-brake on.
If the engine is starting and revving freely, I do not think the "won't budge" issue is related to your hydroboost or power steering system. It would seem to be somewhere between the transmission and brakes.
Since the van is already with a mechanic, I'd let that process play out and see if they can get right. Be wary of follow up diagnoses wanting to replace additional parts.
 

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Discussion Starter · #6 ·
I agree with Mark about flushing the system…. Good idea.

as for the fluid causing the problem…. Not likely. GM recommends power steering fluid. Some run ATF and report no problems. I don’t think the fluid caused the problem.

That said, I notice that often hydroboost “problems” are detected by shops when no problem existed for the owner…. It’s like the system is unknown to them so it is automatically suspect.
There are many ways to go wrong installing a hydroboost. The rod length varies…. Lines leak that did not leak before.

Whenever the system is opened it MUST be bleed…. A lot. The front of the van unloaded (on lift or jacks) must be turned lock to lock 10 times…. 20 times to be safe.

If there is air in the system it will cause problems.

Now, after all I just wrote…. The problem of “grinding” while steering sounds like your idlers are worn and your center link is hitting the harmonic balancer….

Super common problem on AWD vans…. Something a competent mechanic would have found immediately instead of changing a bunch of unrelated parts.

thanks for the thoughts here and I'll be sure to share with current mechanic. As far as the grinding - the first mechanic did identify that the idler arms were bad but that it wasn't an imminent need for repair, but something that would need to be done soon. I definitely noticed the grinding go away after the first replacement of the power steering pump/hydroboost.
 

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Discussion Starter · #7 ·
If the engine is starting and revving freely, I do not think the "won't budge" issue is related to your hydroboost or power steering system. It would seem to be somewhere between the transmission and brakes.
Since the van is already with a mechanic, I'd let that process play out and see if they can get right. Be wary of follow up diagnoses wanting to replace additional parts.
thanks for this. I also thought it would have been the transmission, and the mechanic originally thought it was the front differential but then discovered it was okay.
 

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2003 Safari AWD
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I'm putting one in mine. Our reservoir has no built in filter.

When the fluid comes out of the pump it is now "LOW PRESSURE" and on its way through the cooler then back to the reservoir. This is where you cut the line and insert a power steering filter.
 

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2004 Safari RWD, 2002 Astro AWD
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What type or brand filter do you people suggest?
Does ant body have a photo of one installed.
Does Rock Auto sell such a thing?
 

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Common Sense + Critical Thinking
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All was good but the coolant was low and the transmission fluid was high. Was going to drive it to a shop but when I backed out of the parking spot the car just wouldn't drive any more - no matter how much gas I gave it, it wouldn't budge. It took 3 people to push it back into the parking spot. It felt like the brake system was locked up, but I wasn't on the breaks and I didn't have the e-brake on.
Did it feel like it was trying to move at all or nothing? That can happen with an overfilled transmission. Why is it overfilled, is the fluid contaminated, failed radiator?
 
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