Teves brake troubleshooting (HEMI...HELP!!!)

[Reaper1]

So, I FINALLY got the red 16V car to my house after waiting a MONTH! This isn't the thread for me to go over the car, but rather the specific issue the brakes are giving me.

 

I knew the left front was not working correctly. My friend had replaced the caliper, but noted no fluid coming out of the line, so we suspected a collapsed brake hose. I replaced that and bled it.

 

Something strange I have never come across before was that the new copper washer that came with the new hose didn't seem thick enough and I had to use a thicker washer to get it to seal against the caliper. Even with that I had to really crank down on the banjo bolt to get it to stop leaking. More than I normally would.

 

It seemed to bleed OK, but that caliper will not retract! I drove it maybe 1 block and it was warm to the touch!

 

I busted out my FSM's and started reading. It seems like it could possibly be the release valve inside the Teves hydraulic unit. There is a testing procedure, BUT my question has to do with HOW to accomplish that procedure.

 

When it is telling me to jump terminals on the controller, is this accomplished with a back probe?

 

The test reads:

Bridge pins 16, 35 and 3 and also pins 2 and 8 at the ABCM.

 

The way I interpret that is I am going to jump 3, 16, and 35  together, and separately I am going to jump 2 and 8.

 

Is that correct?

 

I know the book says to NOT open up the unit, but I am positive this issue is because the car just wasn't driven and there's gunk possibly built up. Can it be flushed? I do have 2 other units, so if it needs swapped I am OK, but I'd rather not.

[Hemi Dude]

Just to let you know that I saw your request. Unfortunately I got Covid-19 currently, will get back on this another time.

[Reaper1]

57 minutes ago, Hemi Dude said:

Just to let you know that I saw your request. Unfortunately I got Covid-19 currently, will get back on this another time.

Oh man...I wish you the best! This stuff is no joke!

[Hemi Dude]

13 hours ago, Reaper1 said:

So, I FINALLY got the red 16V car to my house after waiting a MONTH! This isn't the thread for me to go over the car, but rather the specific issue the brakes are giving me.

 

I knew the left front was not working correctly. My friend had replaced the caliper, but noted no fluid coming out of the line, so we suspected a collapsed brake hose. I replaced that and bled it.

 

Something strange I have never come across before was that the new copper washer that came with the new hose didn't seem thick enough and I had to use a thicker washer to get it to seal against the caliper. Even with that I had to really crank down on the banjo bolt to get it to stop leaking. More than I normally would.

 

It seemed to bleed OK, but that caliper will not retract! I drove it maybe 1 block and it was warm to the touch!

 

I busted out my FSM's and started reading. It seems like it could possibly be the release valve inside the Teves hydraulic unit. There is a testing procedure, BUT my question has to do with HOW to accomplish that procedure.

 

When it is telling me to jump terminals on the controller, is this accomplished with a back probe?

 

The test reads:

Bridge pins 16, 35 and 3 and also pins 2 and 8 at the ABCM.

 

The way I interpret that is I am going to jump 3, 16, and 35  together, and separately I am going to jump 2 and 8.

 

Is that correct?

 

I know the book says to NOT open up the unit, but I am positive this issue is because the car just wasn't driven and there's gunk possibly built up. Can it be flushed? I do have 2 other units, so if it needs swapped I am OK, but I'd rather not.

 

This is the MST-6400 test module referred to in the Service Manual. I'm rather sure you do not have such a tester. 

 

Just so I am clear, the caliper in which the piston will not retract, is that the rebuilt caliper on the left front?  If so, if you open the bleeder fitting, does the piston relax it's tension on the pads?  Is this the only caliper that drags the pads heavily against the rotor? You do know that there is always 'some' drag on the pads against the rotor.

The more information you can provide, the better I could "possibly" assist you. What is the status on the accumulator? Original??? If so, you know that it must be replaced.

 

You can PM me or continue here as you see fit.   Be looking for your reply...

[Reaper1]

You are correct, I do not have the tester. Only other person I know with one is clear across the country.

 

Left front, correct.

It is the only caliper dragging, and yes, I understand that there is always some friction (this was like the parking brake was still engaged...on only the front left!)

Yes, accumulator is original, and yes, I have a new replacement ready for it.

 

I need to get back to you on the other answers. In typical PNW fashion it is raining...AGAIN! (we haven't really had a "summer" this year).

 

I am fighting with the fuel rail at the moment. The FPR is shot and I need to replace the lines. I have it loose from the manifold, but I have to get under the car and get the intake brace off and remove the other vacuum fittings. The book says it pulls right out...the book LIES! LOL Good thing it's not my daily...I can work on it as I want, and when it makes me mad, I can walk away!

[Hemi Dude]

Well, you could be down here in AZ where it is DRY and 115 degrees. At least you wouldn't be getting rained on as you crawl under your TC.

According to 'Hoil', once the 2 fuel rail retaining screws are removed, it should pull off. Only the o rings on the injectors should be holding you back.  

Of course you have to disconnect the wiring harness and ground strap. 

I HAD one of those 16V monsters, was glad when someone else wanted it more than me.  

If you go to the Allpar.com website, https://www.allpar.com/model/tc.html it is that yellow one that stares you in the face on the TC page.

Let me know if I can help further when it quits raining up there.

[Reaper1]

Oh, the rail pulls off, but because of all of the vacuum stuff, there's no room to actually pull it out! LOL I even grabbed another intake and rail, mocked the whole thing up on the bench and that's when I knew I had to pull the nipples out of the plenum to get enough room while in the car. I REALLY don't want to pull the intake for a FPR, and I am certain it can be done in the car, it's just being persnickity. I have another regulator, but I ordered a new one anyway because I don't feel like attempting this again!

 

I REALLY wish they had used the flat radiator fan of the 3.0! being able to get that out of the way would make this job SO much easier!

[Nile]

Reaper - I have no idea if this will help, but a few years back I bought a TC that had been started regularly, but not driven.  The prior owner was very open about a brake problem and had replaced all the calipers, rotors, & pads.  When I drove it, the engine & trans were sweet, but the brakes were horrible - the right front was dragging and was the ONLY one that worked, meaning a stab of the brake pedal produced a dramatic pull to the right and smoke from the brake.  Turned out the LEFT front brake hose was plugged.  Replacing that hose, which was an inexpensive and straightforward job solved the problem.  I now had functioning 4 wheel brakes.  Naturally I replaced the other side hose and bled the system.  The brakes have been fine ever since.  I hope your fix is similarly easy.

[Reaper1]

Thank you. I wish I was optimistic about it, but I think the hydraulic unit is messed up. I believe the release valve in the unit is stuck. I am going to mess with it some more today, most likely (provided the weather holds).

[Hemi Dude]

On 7/8/2020 at 8:04 AM, Reaper1 said:

Thank you. I wish I was optimistic about it, but I think the hydraulic unit is messed up. I believe the release valve in the unit is stuck. I am going to mess with it some more today, most likely (provided the weather holds).

Any progress at your end?

[Reaper1]

2 minutes ago, Hemi Dude said:

Any progress at your end?

Not yet. I am hoping to work on it some this afternoon after work. I'm sure as you read, I got her running smoothly, so this is absolutely next on the list!

 

In doing some research, I found that Jaguars, of all cars, have this issue as well. It is caused by the brake fluid not being changed and it absorbing water, then causing corrosion of the valves. Well, that on top of the ribbon connections they used on the solenoids being junk, but that's fixable. Corroded valves are a death sentence for the unit.

 

Anyway, I am going to attempt to do some more troubleshooting today and I'll update.

 

Thanks for checking in!

 

BTW, how are *you* doing? I hope recovering.

[royalcabTC]

Found a youtube video that shows how the Teves systems work. It is an old Chrysler tech video that helps to understand what's going on. It mentions an accompanying tech manual/reference book that I will try to find a pdf of to post.

 

[Reaper1]

I will take a look at that video for sure.

 

Yesterday I just wanted to verify that the caliper wasn't stuck and that fluid was flowing. Both are true, but it is NOT releasing. I have the front of the car in the air, put it in 1st and lightly tap the brakes. It takes a few taps, but the caliper locks up harder and harder each time.

 

I also came across an issue I haven't had before: the copper washers for the banjo connection were too thin! The new hose I put on came with new washers, which I typically like to use. When I put it together the first time I noticed I had to crank the living snot out of the banjo to get it to quit leaking. I bought new washers in the HELP! section...SAME issue! The factory washers are quite a bit thicker. The one that goes against the caliper wasn't even making contact! I ended up reusing the factory ones.

 

I have my known good Teves unit with a good accumulator on it sitting here...I am thinking it's just going to be the best idea to swap the whole darn thing.

[Reaper1]

Well, this was an epic tale of "trust your gut" and "do the simple stuff first".

 

So, I dove into the process of replacing the hydraulic unit. Unhooking it and getting it loose from the firewall wasn't horrible, but the 3 times I have done this before that thing just came right out...NOT this time! Of COURSE! Nope, it just kept getting jammed up on something and would NOT let me get it out! Well...it came out. I decided that when I put the new one in the studs needed to be shorter (which did help a small amount...gotta love porta-bands!) I took care of some potential future rust issues while I was back there, then went about installing the known good unit.

 

Well, it went in the area fairly easy, but I could NOT get it all of the studs to line up! Ugghh...it took me holding my tongue right, but I got it.

 

Get it all put together, go to bleed the system, step on the brakes....*SSSQQQQUUUIIIRRRRTT* To be fair, Rick warned me that rear hard line going into the valve block was a pain...he wasn't lying! I SWORE I had it...I threaded it with my fingers, even got a few turns on it before wrenching on it...little did I know how MUCH I needed to wrench on it! I felt like every time I pulled the wrench would be the last! It finally snugged down and quit leaking, though!

 

Back to bleeding...left front...STILL not acting right. I had to change the banjo AND the washers to get it to quit leaking and it STILL wouldn't retract! I could open the bleeder and force it. I could leave the bleeder closed and force it, but it absolutely would NOT retract on its own. So...I decided I needed to try a different caliper.

 

Here is the lesson: From the start that dumb caliper wasn't acting right. In my gut I was thinking I should just replace it, even though it came off of a fairly low miles car. It was giving me odd problems that just screamed "replace me".

 

After ripping my garage apart, driving to my storage unit, then rummaging around in the rubble that once was an "organized" pile I FINALLY found my spare calipers. 5 minutes of work later...the brakes work as they should!

 

This ENTIRE time the blasted CALIPER that had already been replaced, that replacement caliper was ALSO bad! What a kick in the nuts! Had I followed my gut from the time my buddy told me about it and simply threw another caliper on to begin with, I could have saved myself a LOT of time and aggravation.

 

As an aside, I took the valve block off of the hydraulic unit that I took out of the car. It didn't look horrible and the electrical connections tested good. I did see some pretty nasty fluid coming out of it, though. Honestly, I thought there would be more to see, but unless I choose to "destroy" it, I don't think it's going to come apart.