Rear brake differences

[GlenB]

Hey everyone, I'm new to the site talking to another member on here raymondt recommended I ask the jeep gurus on here as I have an issue that's rather puzzling.

Let me start by saying when I first got the jeep the rear brakes did not work at all was the main issue. jeep was totally stock except I found out that the rear end has possibly been changed at some point because there is no spots for the abs sensors on the diff and the abs plug is just hanging under the gas tank. Thinking that maybe the abs pump had something to do it maybe, I planned on rebuilding it all as I have since totally redone the jeep top to bottom since.

Moving forward I have ripped out the abs pump, p-valve, all new brake lines and hoses, new drums, shoes, adjusters, wheel cylinders, adjuster cables ect I even now changed the master cylinder, replace the stock p-valve with the adustable. And the issue is still there the back brakes just will not work!

I have spent alot of time reading your threads trying everything I could different tricks like the adjuster cables being installed wrong (which I will admit I did do) but I fixed that now, brakes have been bled and re bled many times. Adjusted to the drum over and over again. P-valve is wide open and getting flud slash pressure to the rear brakes that not the issue. They are just not grabbing. I can pull the emergency brake as hard as I can and not stop the rear tires on jack stands without hitting the top of the reach. With my foot all the way down on the brake pedal and the emergency brake applied the wheel can still be spun by hand.

So now on another thread here I have read about these two different brake shoes listed by raybestos brakes but they both use the same drum. Part # 769pg and 538pg both of which are listed for a 1997. Has anyone been down this road? Not knowing what the diff is exactly maybe something as simple as the wrong shoe?

I'm now at a total loss and being 20 grand into this project now and a 2 year build I should be able to figure this out but here I am! Any help would be greatly appreciated

 

[bbaldwin237]

Sorry, I have absolutely no help. But interested in hearing from the experts and want to follow along.

Welcome to the forum!

 

[macleanflood]

Technically the "proportioning valve" is a combo block with a shuttle valve...or so I recall from @mrblaine

Can we see pictures of your master cylinder and valve? I'd at least start there and work my way back.

-Mac

 

[mrblaine]

Hey everyone, I'm new to the site talking to another member on here raymondt recommended I ask the jeep gurus on here as I have an issue that's rather puzzling.

Let me start by saying when I first got the jeep the rear brakes did not work at all was the main issue. jeep was totally stock except I found out that the rear end has possibly been changed at some point because there is no spots for the abs sensors on the diff and the abs plug is just hanging under the gas tank. Thinking that maybe the abs pump had something to do it maybe, I planned on rebuilding it all as I have since totally redone the jeep top to bottom since.

Moving forward I have ripped out the abs pump, p-valve, all new brake lines and hoses, new drums, shoes, adjusters, wheel cylinders, adjuster cables ect I even now changed the master cylinder, replace the stock p-valve with the adustable. And the issue is still there the back brakes just will not work!

I have spent alot of time reading your threads trying everything I could different tricks like the adjuster cables being installed wrong (which I will admit I did do) but I fixed that now, brakes have been bled and re bled many times. Adjusted to the drum over and over again. P-valve is wide open and getting flud slash pressure to the rear brakes that not the issue. They are just not grabbing. I can pull the emergency brake as hard as I can and not stop the rear tires on jack stands without hitting the top of the reach. With my foot all the way down on the brake pedal and the emergency brake applied the wheel can still be spun by hand.

So now on another thread here I have read about these two different brake shoes listed by raybestos brakes but they both use the same drum. Part # 769pg and 538pg both of which are listed for a 1997. Has anyone been down this road? Not knowing what the diff is exactly maybe something as simple as the wrong shoe?

I'm now at a total loss and being 20 grand into this project now and a 2 year build I should be able to figure this out but here I am! Any help would be greatly appreciated

The wrong shoe would or should be evident by how easy the drum fits over them when you install it. If it was a slip fit that took some lining up to do and you have the primary shoe in the front, then it sounds like you have an adjustment issue.

To adjust, loosen the cable splitter under the tub until there is slack in it. Then move to the wheels with the axle on jack stands. Turn the tire by hand, adjust the star wheel until you can feel and hear some resistance when you turn the tire. When you can barely turn it by hand, do the other side.

After both sides are done, go back to the splitter and adjust it until the slack goes away. You can test the slack by pulling down on the splitter and watching the cable move in the housing end. Adjust, pull down watch for movement, stop making it shorter when you have all the slack out. At that point, the parking brake handle should set hard about 3 clicks up from the bottom. Take it for a short drive, while moving slowly, depress the release button and hold it in while apply the parking brake several times without slowing down much to bed the shoes some to the shape of the drums better. Take it back, do the adjustments again the same way and report back.

 

[NskLJ]

Hey everyone, I'm new to the site talking to another member on here raymondt recommended I ask the jeep gurus on here as I have an issue that's rather puzzling.

Let me start by saying when I first got the jeep the rear brakes did not work at all was the main issue. jeep was totally stock except I found out that the rear end has possibly been changed at some point because there is no spots for the abs sensors on the diff and the abs plug is just hanging under the gas tank. Thinking that maybe the abs pump had something to do it maybe, I planned on rebuilding it all as I have since totally redone the jeep top to bottom since.

Moving forward I have ripped out the abs pump, p-valve, all new brake lines and hoses, new drums, shoes, adjusters, wheel cylinders, adjuster cables ect I even now changed the master cylinder, replace the stock p-valve with the adustable. And the issue is still there the back brakes just will not work!

I have spent alot of time reading your threads trying everything I could different tricks like the adjuster cables being installed wrong (which I will admit I did do) but I fixed that now, brakes have been bled and re bled many times. Adjusted to the drum over and over again. P-valve is wide open and getting flud slash pressure to the rear brakes that not the issue. They are just not grabbing. I can pull the emergency brake as hard as I can and not stop the rear tires on jack stands without hitting the top of the reach. With my foot all the way down on the brake pedal and the emergency brake applied the wheel can still be spun by hand.

So now on another thread here I have read about these two different brake shoes listed by raybestos brakes but they both use the same drum. Part # 769pg and 538pg both of which are listed for a 1997. Has anyone been down this road? Not knowing what the diff is exactly maybe something as simple as the wrong shoe?

I'm now at a total loss and being 20 grand into this project now and a 2 year build I should be able to figure this out but here I am! Any help would be greatly appreciated

Good morning and welcome.
To start remove the drums and have someone push the pedal and verify the wheel cylinders are moving. If they are pushing the shoes out. I would measure the brake drum and shoes while installed. From looking at those 2 part numbers both appear to be a 9” shoe. The 538 are 9” x 2 1/2” I did not find the measurement on the 769 shoe.
Here is the tool used to measure the drum then the shoes while installed. You should be able to measure without it, but I wanted you to see the tool to get an idea.
https://www.zoro.com/westward-brake...VWwCtBh2Xgg5BEAQYAiABEgKlNfD_BwE&gclsrc=aw.ds

 

[gasiorv]

The wrong shoe would or should be evident by how easy the drum fits over them when you install it. If it was a slip fit that took some lining up to do and you have the primary shoe in the front, then it sounds like you have an adjustment issue.

To adjust, loosen the cable splitter under the tub until there is slack in it. Then move to the wheels with the axle on jack stands. Turn the tire by hand, adjust the star wheel until you can feel and hear some resistance when you turn the tire. When you can barely turn it by hand, do the other side.

After both sides are done, go back to the splitter and adjust it until the slack goes away. You can test the slack by pulling down on the splitter and watching the cable move in the housing end. Adjust, pull down watch for movement, stop making it shorter when you have all the slack out. At that point, the parking brake handle should set hard about 3 clicks up from the bottom. Take it for a short drive, while moving slowly, depress the release button and hold it in while apply the parking brake several times without slowing down much to bed the shoes some to the shape of the drums better. Take it back, do the adjustments again the same way and report back.

I have Ford Explorer disk brakes on my rear and the backing plates are flipped so that the calipers are installed on the front side using the Wizard brackets for the parking brake. I have adjusted the parking brake numerous times following your advice above and every time when I am done with the adjustment the parking brake works great but only for a short time before they are not holding at all again. Questions: I will have to pull the rotors to verify this statement but I believe the shoes were symmetrical, is there a primary and secondary shoe and if so how do I tell? If there is a primary and secondary on these brakes, and you flip the backing plates, do you also need to flip the shoes? I know I didn't do this because the shoes came preinstalled and I just installed them without making any changes. Could cables be causing my issues, they are original cables and even though they tend to seem to work when I first adjust them, could they be stretching due to age?

 

[mrblaine]

I have Ford Explorer disk brakes on my rear and the backing plates are flipped so that the calipers are installed on the front side using the Wizard brackets for the parking brake. I have adjusted the parking brake numerous times following your advice above and every time when I am done with the adjustment the parking brake works great but only for a short time before they are not holding at all again. Questions: I will have to pull the rotors to verify this statement but I believe the shoes were symmetrical, is there a primary and secondary shoe and if so how do I tell? If there is a primary and secondary on these brakes, and you flip the backing plates, do you also need to flip the shoes? I know I didn't do this because the shoes came preinstalled and I just installed them without making any changes. Could cables be causing my issues, they are original cables and even though they tend to seem to work when I first adjust them, could they be stretching due to age?

First, the shoes don't wear under normal use, they only wear when you drive off with them applied. There is not a primary and secondary, they are all the same shoe. If they aren't staying adjusted, that is very odd unless you are driving on them. The cables in stock form are very robust, you are only applying about 400 lbs of force to the levers and that isn't enough to stretch the cable.

 

[gasiorv]

First, the shoes don't wear under normal use, they only wear when you drive off with them applied. There is not a primary and secondary, they are all the same shoe. If they aren't staying adjusted, that is very odd unless you are driving on them. The cables in stock form are very robust, you are only applying about 400 lbs of force to the levers and that isn't enough to stretch the cable.

Thanks for the quick response. I am definitely not driving on them. It is weird that they are going out of adjustment. I adjust them and they work great, then after a short time the handle seems to start coming up a little higher when pulled and the brakes don't hold at all. This last time, I adjusted them and then after 2 days of driving the jeep to work and to run errands they quit holding again. I will figure it out just wanted to see if there is something obvious that I was missing.