Rear Brakes

[jgmsail]

So I have posted this in several different forums and gotten a few responses about what to try but I am not convinced that any of them are the root cause.

So I have done a lot of work on my car lately. I have put new koni shocks, new upper and lower A-arms, new bushings on the sway bar, new drilled and slotted rotors on all four wheels, new brake pads and replaced the passenger side rear caliper. Have driven it all of about 200 miles. I noticed the rear brakes were dusting pretty bad and putting off a fair amount of heat, I just figured it was wearing the pads in. Today I thought maybe the compensator valve was may malfunctioning so I have bypassed it. After 40 miles they are still putting off excessive heat, the rim measured 200 degrees F and the rotor measured 250 degrees F(per my infrared thermometer) in contrast the front rims were 118 degrees F and the front rotor was 124 degrees F. I do not use the brakes much as I tend to use the transmission to slow down.

So I am now going to replace the center brake hose and possibly reset the hand brake. The hand brake is coming up further than it was probably 5 to 6 clicks before it gets tight. Both wheels are getting hot so either of these could be the fix. I will probably connect the compensator back up as it has not had any effect on the issue. When I inspected the front disc they are only wearing in on the top inch of the disc, not sure what to make of this right now.
Any thoughts would be appreciated thanks

[Exit98]

Just some rambling thoughts. I'm no expert on brakes or anything else.

I suspect it may be your real calipers although why both would be bad is a question.

I was going to suggest loosening the EB cable to slack, but if its an EB problem it isn't the cable but the levers on the calipers that are the issue.

When you jack up a rear wheel does it turn easily or are the pads dragging on the disc? Replacing the center rear brake line is easy enough. I suppose it could be kinked or partially blocked not allowing the fluid to return.

Front pad issue sounds strange. Are your wedges in proper orientation?

[DieselSpider]

If the pistons aren't retracting properly then the self adjusters are not going to rotate and keep the rear calipers adjusted. When a brake hose starts to come apart internally it many times breaks its inner liner at the outgoing crimp connector and acts like a one way valve keeping the pads in contact with the rotors causing brake heat and dusting. This is a very common issue and one reason they recommend changing the rubber brake hoses at least every 10 years with a 5/6 year replacement schedule preferred. Not flushing the brake fluid every 2 years will add to the problem as the fluid absorbs water and turns acidic eating away at your brake system from the inside out.

Its time to replace all the rubber brake hoses that are over 5 years old and fully flush the system to ensure all rotten hose debris is removed from the system. The kits to rebuild both rear calipers are less than $20 and a real bargain considering the cost of having to completely replace them if you let them go too far.

[jgmsail]

Thanks for the information, I am hoping to get to work on it next weekend. I will post what we find.

[blazingspider]

You have the right pads for the rear correct? They are much thinner than the fronts. Also there's a tab on the back of the pads that fit into a slot on the caliper piston. The caliper piston also needs to be oriented properly in order to be able to bleed the rears. There's a scribed horizontal line on the piston face that follows along the slot. That line should be oriented at the top when looking at the caliper. If not, rotate the piston until it is.

Also, rear brake performance is affected by the correct e-brake adjustment. Loosen the cable, step on the brake pedal a few times, and then tighten the cable until the e-brake engages in 3 clicks.

Hope this helps.

[jgmsail]

So thanks to all for the help with the rear brakes. It turned out that the center rubber hose had total closed off, I could not even blow any air through it using 80 psi compressed air. It now has all new braided hoses on each caliper and a new center hose. I still have one issue I am working on but will post it under the suspension page.

[DieselSpider]

Just remember that if you reconnected the rear compensator valve that the rear axle needs to have the weight it of the car on it with the axle supported by jack stands in order to bleed the rear brakes.