Baystate Jeepers

A couple of weeks before Fall Crawl I noticed my brakes squeal at low speed. I thought the pads just needed some anti-squeal compound. While airing down at the Crawl, I found out the left rear wheel was really HOT from 20 minutes of driving. However, it didn't get hot on the trail though. My assumption was that either the bearing is going bad or binding caliper. Took everything apart when I got home. Bearing looks new and the caliper is good and I applied some anti-squeal compound on the pads. Put everything back together and took a 20 minutes drive. Left rear wheel still gets really hot. Now I am at a lost. The only thing I can think of is the residual valve is holding to much pressure for the calipers in the rear. The stock xj setup has drum brakes in the back. I've upgraded to use Caddy disc but still using the stock MC and proportioning valve. Would this be the problem? Does anyone know where the residual valve is located in the stock '99 4.0 xj? Thanks in advance for your help.

I would replace the caliper. I had the same issue with my front right after the jeep sat. Replaced both calipers at at same time nad the problem went away.. probably hanging up...

If it was the residual valve, both rear brakes would be dragging. On a front disk / rear drum system, there is typically only one valve for the rear. It is in the master cylinder or proportionating block.

What is the history of the brakes? Are they new, used, etc?

Is the parking brake incorporated into the caliper (Caddy style) or hat style in the rotor?

Joe, the Caddy calipers are like new - less than a year old. These are not re-manufactured units. They do have e-brakes incorporated. Jeep has good stopping power and the e-brake works. If I jack up the rear and spin the tires, I can feel more drag on the left than right. The left do spin but just not easily. Could it be because the right is further away and has less effect from the residual pressure?

I am going to try to swap in a proportioning block made for 4 disc setup (if I can find one). I think the residual valve is part of the block. I looked up the part number for the MC for 4 disc ZJ and it's the same as XJ. So the difference is got to be in the block.

Jeff, I might look into getting just the left rear. Caddy caliper is crazy expensive!

norstar wrote:Joe, the Caddy calipers are like new - less than a year old. These are not re-manufactured units. They do have e-brakes incorporated. Jeep has good stopping power and the e-brake works. If I jack up the rear and spin the tires, I can feel more drag on the left than right. The left do spin but just not easily. Could it be because the right is further away and has less effect from the residual pressure?

I am going to try to swap in a proportioning block made for 4 disc setup (if I can find one). I think the residual valve is part of the block. I looked up the part number for the MC for 4 disc ZJ and it's the same as XJ. So the difference is got to be in the block.

Jeff, I might look into getting just the left rear. Caddy caliper is crazy expensive!

FWIW, I replaced the rear calipers on Angie's Maxx last year and the driver's rear parking brake is sticking. They were new too. Regarding the distance between the right and left, in that small a hydro system it won't make a difference.

IMO, the symptom's leave me to believe it's a caliper hanging. Do you use the parking brake often? Often times on the integral calipers, the brake will hold up due to the parking brake mechanism than a hydraulic issue. It doesn't take much movement of the arm to invoke a drag. Make sure the E-brake lever is retracted all the way, manually pry if you have to, and then go for a test drive.

I also switched to Eldorado calipers in the rear. The proper way to adjust the park brake is move the arms till they wont move any more. I had drag on release also. I put stronger springs on the cable bracket to release that arm better. It seams to work good now. Look to see if both arms move the same amount, you may have a sticking cable on that side. FjR68

If they are under a year old they may be under warranty... may want to call whoever you bought them from...

ZAEDOCK wrote: Do you use the parking brake often? Often times on the integral calipers, the brake will hold up due to the parking brake mechanism than a hydraulic issue. It doesn't take much movement of the arm to invoke a drag. Make sure the E-brake lever is retracted all the way, manually pry if you have to, and then go for a test drive.

Yep, use the parking brake all the time. The lever arm returns to the stop on the caliper fully.

Frank wrote:I also switched to Eldorado calipers in the rear. The proper way to adjust the park brake is move the arms till they wont move any more. I had drag on release also. I put stronger springs on the cable bracket to release that arm better. It seams to work good now. Look to see if both arms move the same amount, you may have a sticking cable on that side. FjR68

Eldorado calipers are PITA. They are great when they work but very difficult to get them adjusted properly. I've searched all over and read through numerous write ups on caliper adjustment on pirates, custom brake vendors and whatever showed up from google. I still can't get the darn thing to adjust properly. Yep, I even got a new (reman) one from AZ. If I set it to no drag then the e-brake won't hold. If the e-brake is set correctly then the rotor gets hot! I'm tired of adjusting the rear calipers and had to take them off to perform "gravity bleed". That's right! I have to take them off to bleed because the bleeder is not on top of the caliper and I can't step on the brake paddle while they're off. I don't remember I spent that much time installing them the first time. Frank, I might need your help.

Voodoo Chile wrote:If they are under a year old they may be under warranty... may want to call whoever you bought them from...

I got these new from TSM because the calipers ( at $150 a piece) come with e-brake hardware. The ones from Rockauto, AZ and Advanced don't.

Bleeders not on top?
Are you sure you have them installed on the correct side?
Passengers vs drivers side.

Kurt, I guess the bleeders are on top but slightly below the piston? The way they are mounted on the TSM brackets the bleeder are pointed down and definitely not on top. I hope I didn't get my left and right mixed up. I put the one with an "L" on the casting on the driver side rear.

You do have to bleed them off . They have a gizmo that you plug into the bleeder and then press the brake pedal 3 times and close the bleeder and move on to the next one. Cheep ones are like 10.00. It makes it alot faster. FjR68

Ah yes... gizmo = Speed Bleeders. They replace you regular bleeders on the calipers.

I had Eldo calipers on the 14 bolt of my old truck. There are two types of Eldo calipers though, old and new (smaller). Mine were '76-78-ish. You probably have the smaller '79-85. Either way, bleeders should be on top.

Is this your kit?
http://www.tsmmfg.com/2563_44.htm

I might have to get some speed bleeders...

Yep, the smaller '79-85 version.
I use this kit. http://www.tsmmfg.com/2562_44.htm

Rented a caliper tool from AZ. The brakes are running cool now. Parking brake will hold in "D" and "R" but not too good on an incline though. Oh well...