Hi, I had just replaced my front & rear pads. I have done around 150 miles since I did the job & the brakes are working better than they have for a long time. All of the caliper pistons were VERY easy to push back in & the sliders, although they were free, I removed, cleaned & lubed them all. All of the rubbers were in good condition with no tears etc. All the new pads were a good fit in the calipers & are able to move freely.
Problem i'm having is that the rear brakes seem to be dragging a little, after a half hour 70mph freeway drive I can actually smell something getting hot at the back of the vehicle & the rear wheels are quite warm to touch - although not red hot like the ones on my old Volvo station wagon were when I had a similar problem. They cannot be dragging much because the vehicle creeps forward in traffic if I take my foot off the brake when i'm in gear.
What have I done wrong here because the problem wasn't occuring before I changed the pads?
Any help would be appreciated?

 

Jack up the back end of the truck and support it on jack stands. With the engine running & transmission in neutral, have someone behind the wheel ready to push on the brakes. While you spin the wheel, have them hit the brakes until the wheel stops. Once the wheel stops, have them continue to hold the brake pedal down. Get ready to spin the wheel again and have them let up on the pedal. If you cannot spin the wheel quickly after the pedal is released, there is a problem with one of the flex lines.

If both sides are affected, it could be the main flex line from the frame to the rear axle. If only one side is affected, it is likely a problem with the flex line at that caliper. If you are going to replace one of them, I would recommend replacing them all.

 

Thank you very much for the quick reply - I hadn't even thought about the flex lines. I'm pretty sure they are the ones that the vehicle left the Linden NJ factory with so they could well be past their best after 11 years?
What you have suggested is gonna be my 1st job tomorrow as it's bucketing down with rain today, supposed be better in the morning though.
Will let you know what I find.

 

Dave,

I had a sticking caliper on my trooper at the back and the damn thing even after a short journey was so hot you couldn't touch it and it even smoked after a longer journey, got so hot on one occasion I had to pee on it to cool it down as I was scared it was going to catch fire! Looking at the Blazer brakes they are very similar calipers, not a surpriuse as they come from the time when GM owned a big chunk of Isuzu. I suspect mine all need a good clean and grease as they seem very stiff, pedal doesn't feel right and last time I felt a pedal like this it was down to sticky sliders.

I have had a flexi pipe do just that this, on a suzuki Sj we used to own, it was acting as a one way valve and letting fluid through but not back (well back very slowly) so that could well be the problem. It may just be holding the pads on the disk very slightly.

Mind you, I reckon the spark plugs I changed last week on mine were the originals!

 

2nd Gen Blazer are well known the have the read caliper pistons fail after a pad replacement, especially original calipers. The results of replacing rear pads without rebuilt calipers is the pads never free after pressure is applied, and the vehicle drags and rear brakes heat up.

Do yourself a favor and order two rebuilt rear calipers and your problem will likely be solved.

 

Thats a bit of a fundamental design issue if you can't change pads without having to rebuild the calipers. I'm not a big fan of the japanese style single pot calipers myself having had my share of problems with them on my troopers but I've never heard of a problem like this with them. Sometimes it can be that there is a ring of rust that builds up on the end of the piston as rear brakes often wear very slowly, shoving the piston back in to fit new pads means the rusty bit is now inside the cylinder and can stick. If that is the case it can usually be addressed by stripping the caliper down and carefully cleaning the piston with some fine wet and dry if its not scored.

Dave, if it is the calipers then try getting a price from these guys to have them rebuilt, they do a great job apparently and they come back like new and generally its a lot less than a new caliper

http://www.biggred.co.uk/caliperpricing.html

 

I had a problem like this after I did the pads and rotors on my Blazer.
Both rear cylinders failed.
I called a friend of mine who is a GM mechanic and he told me it's a common problem on these trucks.

 

Well this is strange.
I did what Swatlkk suggested at the weekend & everything seemed to check out OK? Didn't have as much spare time as i'd hoped that day but concluded that the flex hoses were OK as far as I could tell. Also the caliper pistons are so free that I can push them back by hand so I find it hard to believe there's any restriction in any of the lines? Also truck (and therefore brakes) were cold & problem doesn't seem to occur until i've driven a few miles & things have heated up a bit.
Had to do a 60 mile round trip again yesterday, got back & I could smell that the rear brakes were hot again. Jacked truck up, removed both rear wheels & found that both sides could be turned by hand - but with considerable effort.
Unbolted calipers & when I went to remove the pads they were VERY hot & very difficult to remove. When I fitted them last week they were a nice sliding fit - but they were cold then. Wondered whether expansion due to heat was enough to make them bind up? Spent a few minutes with the bench grinder shaving off a tiny little amount from the edges of each pad & replaced them.
Put everything back together & went for a 20 mile drive to try & get everything hot again, making sure I gave the brakes a good bit of use.
I am pleased to report that the problem is now solved! Got back, jacked vehicle up & both rear wheels turn freely & there is minimal heat from the brakes.
My next move was gonna be to order 2 new/rebuilt calipers. Hopefully they'll stay that way for a while yet?
I guess aftermarket pads are not always so precisely made as the GM ones. Probabaly explains why they're twice the price though?
Looking at other posts on this forum it does indeed appear that the rear calipers on these trucks DO give problems but I guess i've got away with it for now?