Brakes fading/over heating

[88eliminator]

Hello,

I have an 1988 jeep Comanche Eliminator used as a daily driver with an overheating brake problem.

 

I just replaced the front disc with slotted rotors and new pads and also replaced the rear drum shoes to. The brakes work good until you go down hills. When going down hills I can start to feel the brakes fade and then the brake peddle goes to the floor with the truck slowly coming to a stop and I have to pull over because I have no brakes. Even when I pump the brakes that doesn't help ether. 

I don't ride my brakes and usually use engine braking.

 

I was wondering if my master cylinder is going bad? The brake fluid is not that new but i'm going to bleed the brakes and put new fluid in.

I heard that the brake boosters are bad in the 1988 jeeps? is that true or not?

 

Any advise needed, 

Thanks.

 

    

[Strokermjcomanche]

I would start with changing the booster / master cylinder with a 95 / 96 cherokee or a 99 + WJ setup . Also I would check and see if your load sensing valve above the rear axle is working and the rod is attached to it . Chances are the booster is the culprit , but it's worth checking / replacing with the newer dual diaphragm booster .

[88eliminator]

I definitely will look in to that. Thanks so much for the advice.

[Eagle]

Why would a bad booster cause the brakes to fade, only when going downhill? That doesn't compute. Brake fade is almost always caused be heat, and if the brake fluid isn't fairly fresh that's the first thing I would look at. Next thing would be a caliper that's hanging up and dragging.

 

Did the 88's have bad boosters? That's very subjective. My '88 XJ has 287,000 miles on it, and it still has the original booster. No complaints from this corner.

[88eliminator]

Yeah I'm definitely going to change and bleed the brakes before I think about doing anything else on the brakes. The truck has been sitting for years when my grandma had it about 6 mounths ago but always went in to the shop to change the fluids. Now that I inherited the truck from her I am slowly tuning it up and fixing what needs to be fixed.

 

The truck only has about 79,000 original miles on it and have been experiencing the brakes overheating and fading. I think that when it used the sit all the time that things are slowly failing now that I drive it everyday.

 

Why would a bad booster cause the brakes to fade, only when going downhill? That doesn't compute. Brake fade is almost always caused be heat, and if the brake fluid isn't fairly fresh that's the first thing I would look at. Next thing would be a caliper that's hanging up and dragging.

Did the 88's have bad boosters? That's very subjective. My '88 XJ has 287,000 miles on it, and it still has the original booster. No complaints from this corner.

[Eagle]

If it has been sitting for a long time I suspect a frozen caliper. Either the caliper is stock and can't slide on the mounting pins, or the piston is stuck inside the caliper and isn't fully releasing when you take your foot off the brakes.

[benjy_26]

Something's definitely dragging. Check the calipers. I have an 87 that I'm daily driving right now and I go up and down a mountain pass pretty much on a daily basis and my bone stock brakes don't cook themselves.