2003 WJ - Soft Brakes

[Dredwolf]

Driving the WJ during work today, noticed the brake pedal getting spongy, and would almost bleed down sitting in traffic. :bang:

Checked fluid level, its fine, changed pads two weeks ago. Not seeing leaks, no hissing like a typical failing booster. :confused:

I would LIKE to replace all the calipers, fresh rotors, and go ahead and change the brake lines to stainless in advance of the lift, but budgets declare otherwise. :rolleye0012:

Are these WJ's known for soft brakes? Does it end up usually being the booster or the master cylinder? Figure both will have to be done, but budget says I can only do one at the time.

[4.3LXJ]

Usually soft brakes that will bleed down are indicative of a worn master cylinder. Not hard to change. If you do, bench bleed it first and it will be much easier

[Dredwolf]

Usually soft brakes that will bleed down are indicative of a worn master cylinder. Not hard to change. If you do, bench bleed it first and it will be much easier


I was thinking similarly, so master cylinder gets the vote for 1st to replace, and we'll go from there.

[Dredwolf]

Well, replaced the master cylinder today, the included bench bleeding kit was a joke.

Going to pick up better kit to keep around.

At this point, no idea if that solved the spongy brake pedal, but I suspect it has not.

But that will have to wait until I replace the passenger side rear caliper that has a seized bleed screw in it :bang:.

If it ends up not being the master cylinder, guess a booster is next?

[4.3LXJ]

If that master is good, then your soft pedal should go away with good bleeding. The booster really should not affect a soft pedal. It is just an assist

[Charlie Foxtrot]

Sinking pedal = leak
Leak can be external (wet spot somewhere) or internal (no wet spot).
Internal leaks are usually found to be in the master although they can show up in ABS &/or the proportioning (balance) valve.
To diagnose a master cylinder leak, you will need threaded plugs for the master. Do not use pipe plugs, they are the wrong thread. You can make plugs from the correct size steel line double flare fittings by brazing (or silver soldering) the opening in the fitting. Remove the lines coming out of the master & install the plugs. Now try to push the pedal - if it sinks, the master is leaking internally. If you are trying this on a new master, bench bleed the master first, before installing. If it doesn't sink, you need to start looking for the wet spot. Get a friend to help. Fill the master, install the cap, & have the friend start pumping the brake (gently). No need for stomping. Check all the steel lines, the hoses (bulging = bad), and the various brake components (calipers, bleeders, banjo bolts, splitters/Tees).
As a matter of preventative maintenance, its a good idea to flush the brake hydraulics every couple of years. Brake fluid (all but DOT 5) is hygroscopic - it absorbs water from the air. This water can rot the steel from the inside out., or pit your caliper bore, or wheel cylinder (heck, even the master cylinder bore). The corrosion will cut the o-ring or cup as it passes over - instant leak.

If you plan on doing more than one brake job in your lifetime, spend fifty bucks & buy/build a power brake bleeder. They are worth their weight in Big Macs. They save lots of time & major aggravation when doing brake jobs.

For rusted bleeders, my last ditch method is Kroil, time & gentle heat (propane, not Oxy-Acetylene) and ALWAYS use a 6 point wrench. I like a quick dot of Teflon dope on the threads when re-assembling (no petro base oil/grease/never-seize). Make sure the dope is only on the threads. We don't want bits of Teflon in the brake system.

Good luck & keep us posted.

[Dredwolf]

I'll be honest, feeling very beat at this point...it's been quite the automotive minefield here for the past several months, with a perfect storm of failures starting with the wife's 2003 Explorer. The Explorer is an entire thread by itself, but it's finally back on the road....and I hate the timing chain arrangement and thermostat housing on that motor....it's clean as a pin inside thanks to synthetic oil, and some of the parts got covered by warranty, but damn...

:rant: In front of my garage tonight, I currently have 4 non-driveable vehicles, and one in the garage, with 4 of them being 4x4, but all with issues I could fix if I could be left alone for an entire weekend versus working on them in the driveway at night, and being interrupted every time I start making progress.

If anyone was close enough, I'd throw a wrenching party, supply the beer, and grill the burgers and hot dogs.

When you are feeling beat by something as simple as bleeding the brakes after replacing the caliper with the seized bleeder screw, time to call out for help. So I am.

I use Kroil myself, with 6-point drive brake bleeder wrenches, NORMALLY. However, normal is not happening. After replacing the caliper tonight, I can get nothing more from the passenger rear brake line than a drip...even with my wife pumping the brakes, a full reservoir, and the fitting disconnected.:confused:

The master cylinder that I replaced actually appeared to be of better quality than what I installed two days ago, and did not have the right appearance to the original, so I suspect this has been a problem for awhile. The ABS lines appear to never have been touched, I would say the same for the proportioning valve. So it's a matter of tracking this down, and trying to not go broke(er) in the process. The core charges on the brake calipers out here are more than the parts, I found out today.:bang:

[Dredwolf]

After replacing the caliper tonight, I can get nothing more from the passenger rear brake line than a drip...even with my wife pumping the brakes, a full reservoir, and the fitting disconnected.:confused:


Answered my question in a few minutes after stepping away from the problem and clearing my head....staring at the blasted ABS unit and rusty lines and forgot I needed to use a scan tool to activate it since I replaced the master cylinder....:rolleye0012:

Need to stop wrenching at night.

[Dredwolf]

Answered my question in a few minutes after stepping away from the problem and clearing my head....staring at the blasted ABS unit and rusty lines and forgot I needed to use a scan tool to activate it since I replaced the master cylinder....:rolleye0012:

Need to stop wrenching at night.

Well, this is getting better by the minute...looks like the only thing that will activate the ABS is a stealership scan tool....I can't be the only one that has battled this, and there has to be some option other than taking it to the local dealer that is known to ruin vehicles.

[Dredwolf]

Well, I hate ABS....when it comes to bleeding brakes.

Right now, the WJ effectively has no brakes....the piston in the new rear caliper does not move....even though brake fluid drips from the bleeder screw.

The bleeder screw in the driver side rear caliper is seized up also, I'll have to pull that caliper to free up the bleeder screw.

I'll admit I did a full on bone-headed move :bang: in replacing the master cylinder without reading a manual or the FSM, and bench bleeding the master cylinder was pretty much pointless, looks like opening the system turned the ABS module into a $$ metal cork in the brake system.

Having long gravel driveway might have worked to trick the ABS system into modulating with some panic stops....except for the yards-long skid marks I am leaving in my pastures trying to halt a WJ with nothing but the parking brake and creative steering....:shocker:

There has got to be something other than a $2K scan tool that can trip the ABS valves and let the brake fluid move. I don't mind the idea of buying a pressure bleeder if that will help me get past this, because the vehicle can't be driven at this time....no brake pedal if the vehicle is running, and nothing creates any drag on the wheels except the parking brake or shifting down.

[4.3LXJ]

Something to try. Fill the brake cylinder with fluid and then compress it. That will force the fluid back through the system. Maybe that will reset it

[Dredwolf]

Something to try. Fill the brake cylinder with fluid and then compress it. That will force the fluid back through the system. Maybe that will reset it

Worth a shot, I am going to invest in a pressure bleeder, as this is a major pain at the moment.

I have the parts for the ABS delete in the XJ, including the proportioning valve, but this WJ is different.

As I dig through options for the scanner (I HATE being FORCED to a dealer), its worth mentioning for those that don't know that the Harbor Freight scanners are actually manufactured by Autel, and with some careful work, you can update the HF Centech scanners with the Autel firmware.

http://www.auteltech.com/

It won't help with my ABS, but I updated my Centech Item 98614 with the Autel Maxiscan MS509 firmware, and it added features the Centech firmware did not have.

So don't rule out the HF scanners, the Autel stuff works decent, I think they make the inspection cameras too, I use the one I have quite often.

[4.3LXJ]

John, if it helps I have a module that was parked in working condition

[Dredwolf]

John, if it helps I have a module that was parked in working condition

Thanks, I may need it. I'll be glad to pay for it and the shipping, of course.

During the course of this silliness with brakes tonight, I found the D35 in the back of this WJ has a leaking oil seal on passenger side axle....glad I own a press.

I am going to try once more to bleed this blasted vehicle with daylight to spare.

I have been avoiding bothering my neighbor that helped with the 2003 Explorer for the past month, as that repair about killed us both (and drained both wallets), but he may have a Chrysler factory scan tool, he runs a professional mechanic shop out of his property. I'll post the saga about the Explorer in the non-jeep thread.

[4.3LXJ]

If you lived near me, you could have a D44 out of the 99

[bluedragon436]

Worth a shot, I am going to invest in a pressure bleeder, as this is a major pain at the moment.

I have the parts for the ABS delete in the XJ, including the proportioning valve, but this WJ is different.

As I dig through options for the scanner (I HATE being FORCED to a dealer), its worth mentioning for those that don't know that the Harbor Freight scanners are actually manufactured by Autel, and with some careful work, you can update the HF Centech scanners with the Autel firmware.

http://www.auteltech.com/

It won't help with my ABS, but I updated my Centech Item 98614 with the Autel Maxiscan MS509 firmware, and it added features the Centech firmware did not have.

So don't rule out the HF scanners, the Autel stuff works decent, I think they make the inspection cameras too, I use the one I have quite often.

Have been looking at picking up one of HF's better scan tools.. I have a basic one just for checking codes and resetting them.. Not sure which one the 98614 is, as all the ones they have now seem to be model numbers starting with 6.. I will have to say I'm glad that my XJ doesn't have ABS, would hate having to fight with a brick in the system any time you do any work on the brake system..

[Dredwolf]

If you lived near me, you could have a D44 out of the 99

Don't rule that out, I have two family friends that are long-haul truckers that are often in California every few months, and I have never called in any favors at this point.

But first things first.

[4.3LXJ]

Don't rule that out, I have two family friends that are long-haul truckers that are often in California every few months, and I have never called in any favors at this point.

But first things first.

Let me know soon. We will be hauling the shell of soon. We can pull the rear end and save it. Minus the rear calipers and discs. Those are on my Jeep :D Wheels and tires available too, tail lights one headlight. All spendy stuff

[Dredwolf]

Have been looking at picking up one of HF's better scan tools.. I have a basic one just for checking codes and resetting them.. Not sure which one the 98614 is, as all the ones they have now seem to be model numbers starting with 6.. I will have to say I'm glad that my XJ doesn't have ABS, would hate having to fight with a brick in the system any time you do any work on the brake system..

With some digging, you can match the units...

http://www.harborfreight.com/obd-ii-can-professional-scan-tool-60694.html

http://www.autel.com/autelcms/Code%20Readers&Code%20Scanners/360.jhtml

Believe these two are the same, but someone out there on the Internet may have already matched them.

[Dredwolf]

So back to the brakes....Going to try Steve's suggestion, along with getting all 4 wheels of the ground so I have good access, and soaking the bleeder screws with Kroil.

The suggestion of a little Teflon dope on the bleeders threads is a good one, as I have to use anti-seize on everything else, so it makes sense.

I looked at the Motive power bleeders, but apparently you need the exact right cap to make them work?:confused:

[Charlie Foxtrot]

I have a Motive, and it works great. For caps, if my universal cap doesn't fit, a trip to the JY for a cap and a little fab work & a quick disconnect, bingo!

Another tip - I frequently use a product called 'Speed Bleeder' (888.879.7016). After using them for years, I found out by chance that the company is located a couple of miles from me (rural northern Illinois). It's a bleeder screw with a built in check valve. You crack open the bleeder, depress the pedal slowly, then release. The check valve keeps you from sucking air back into the system. A few pumps, then close the bleeder, move on to the next wheel (keep the master topped off and the cap on while pumping). A couple laps around the car, & the air is out of the system and the fluid has been replaced. Use a can to catch the fluid (no need to make a mess). BTW Speed Bleeder already has the anti seize on the threads. It is a nice product for a one man shop. It's cheap, easy to use, and most bleeder screws are rusty & plugged so they will need replacement. Might as well use these. I try to keep a few on hand, and the local indy foreign car parts store stocks the common ones. (http://speedbleeder.com/)

[Dredwolf]

So I finally got the WJ back on the road...brakes are bled, and the pedal is better, but still a little spongy.

Given I have to do bearing and seals in the rear axle, going to look at replacing all the calipers and flex lines, and see what that gets me. Thanks to time and patience, rest of the bleeder screws came loose fine, all needed Kroil and time, one needed some propane heat.

Trying to go at the brakes again made me realize I had not replaced tools that had broken since I last turned wrenches for living, so that morning, I went to pick up a Mityvac kit from Harbor Freight, and I spotted this...
http://www.harborfreight.com/automotive-motorcycle/brakes/brake-fluid-bleeder-92924.html

Now, historically, if its possible to spill brake fluid some place, I have done it. I have bought and made dozens of bleeder containers, and still made a mess (but contributed to Oil-Dri's coffers), but this tool was interesting. Checking the reviews on my phone, and 25% off coupon put it into the "why not?" realm.

Took it home, added the air line adapter with tape, glanced through the directions, and fed an air line outside. Hooked it up to the passenger rear caliper, made sure my bleeder wrench was ready, and the master cylinder reservoir was full, slowly pressed the trigger and opened the bleeder......

:shocker: THATS FRICKIN' AMAZING!!!!!! in a few seconds, I had clear DOT 3 visible in the line to the catch tank, and dark brown DOT 3 in the catch tank...closed the bleeder, started removing connector from the bleeder and released the trigger. For the first time I can ever remember, I did not spill a SINGLE drop. Checked the level in the master cylinder reservoir, added fluid, and proceeded around the WJ....in a few minutes, the system was flushed, and the pedal was normal for the first time since I bought this WJ. Shifted back to "manual" bleed mode with some help from my son...there was nothing to do, system was good to go. Little test run around the farm, then up the road to pick up dinner for the family.

Obviously, HF stuff can also be junk too, but this was money well spent, both to quickly handle 95% of the air bleeding, and also to flush a brake system. Yes, the refill bottle is impractical, there are few hoods that is will clear if installed on the master cylinder, but if I get to at least use this thing once on my remaining vehicles, its paid for itself.

[XjKingz]

Try adjusting your brake shoes the help my brakes.


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[abebehrmann]

Trying to go at the brakes again made me realize I had not replaced tools that had broken since I last turned wrenches for living, so that morning, I went to pick up a Mityvac kit from Harbor Freight, and I spotted this...
http://www.harborfreight.com/automotive-motorcycle/brakes/brake-fluid-bleeder-92924.html
.

I have that same power brake bleeder from Harbor Freight. I've only used it once but it worked great. The automatic brake fluid reservoir refiller even works with the XJ.