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Rear wheel getting hot

3K views 15 replies 10 participants last post by  Daddytoeface 
#1 ·
Hello folks I have a question regarding my left rear disk brakes 2005 astro RWD. My wheel was getting really hot after driving. I replaced the following. rotor, parking brake shoe and adjusted, brake hose, slide pins cleaned caliper and replaced the seals and bled brakes. The pads are only a few months old however the inside pad had more ware. Your input will be appreciated and I will post problem once resolved. Thanks
 
#4 ·
Dragging caliper ! So far you have done everything except the obvious. Change the caliper,

or rebuild it. Check to see if there is any rust on the piston(s). (underneath of the dust seal)

Uncle Bob
 
#5 ·
I took the caliper apart replaced the round square seal and the dust boot. Both the piston and cylinder were shiny smooth and clean and the seals were in good shape. I lubed piston, cylinder and seals with new brake fluid it was a struggle getting the piston back in. When I finally did get the piston to the bottom it appeared to be sitting in the cylinder slightly crooked. That did not make much sense to me as there is not much clearance. Is it possible to distort the seal seating the piston and if so would it not straighten it self out afterward? The slider pins were replaced and greased. In a nutshell this would be a rebuilt caliper.
 
#8 ·
Bore must be the problem. Piston shouldn't be all that hard to push into the bore.

Makes sense since it is a O ring seal fit.

Uncle Bob
 
#9 ·
On one of my cars I had the same issue , but I did replace the caliper , rotor and pads ... turn out it was the rubber flex line that was collapsing internally it wouldn't let all the fluid go back to master , it would cool and expand eventually releasing the caliper it looked good Took a while to chase it down . The temp on that one wheel was over double than the other three .

Just a thought
 
#11 ·
I had to replace the rear calipers twice a couple years apart. on my '04 cargo. 2ed time I installed new dust shields as mine were turning to dust and letting to much road salt / crud get at them I guess. Fronts never cause a problem on the gen3s.
 
#12 ·
Yup for the price of a re-man caliper it is worth it . I was stubborn on my old car too . What freaked me out was the old caliper wasn't seized I replaced it ,and the brand new caliper , rotor and pads still did the exact same thing . I talked to a mechanic and he led me too the flex line . It was only on the one wheel so that ruled out an issue with the master , It all made sence seeing as how the line was the only part left .
 
#13 ·
DRZ said:
I had to replace the rear calipers twice a couple years apart. on my '04 cargo. 2ed time I installed new dust shields as mine were turning to dust and letting to much road salt / crud get at them I guess. Fronts never cause a problem on the gen3s.
Yup.

Makes sure those pins are greased, replace the line ( because it's the cheapest part) then test drive. Same problem? New caliper.
 
#14 ·
Daddytoeface said:
...When I finally did get the piston to the bottom it appeared to be sitting in the cylinder slightly crooked. That did not make much sense to me as there is not much clearance...
Remove and dismantle the caliper and run it through the parts cleaner. Take it to a welder and have him TIG weld in a layer of metal on the ID of the cylinder. Then take it to a machine shop and ask them to re-bore the cylinder hole square to the caliper and appropriately oversized to fit the piston. Then parts wash it again, replace old piston with new piston...

Or simply replace the calipers.

Lump
 
#16 ·
This is a follow up to my post. Replacing the whole caliper unit seems to have corrected the overheating issue no more red hot wheel and van shuddering at higher speeds.

For the time and trouble to rebuild the caliper and end up with the same overheating issue in my opinion it is not worth it. Best to buy a new part and be done with it

You can tell by the pictures the piston is not square in the bore and the square cut seal may not have been retracting. It may have been like this prior to the rebuild but I cant be certain.
 

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