'98 Reatta

[fun car guy]

So, having tucked my Reatta away for the winter, I've done some research and it seems the ABS module isn't the only possible solution as to why all brake fluid has stopped on the front left wheel when I know it was flowing before.  I see there's a sort of device labeled the EBCM responsible for distribution of fluid depending on which wheel needs more.  Has anyone encountered this, surely someone has.  If so, please enlighten me before I start taking the master apart come spring.  Also, why do we need a battery shutoff?   I Just put a trickle charger on it.

[Padgett]

The EBCM (ABS controller) send signals to the ABS valve body at the master cylinder saying which valves to open or close. I sounds like you have a stuck valve but that should trip an ABS code. A collapsed or blocked hose could also block a caliper without triggering a code.

[fun car guy]

Thanks but I've pulled the line from the ABS module and it was totally dry and since I know they both were working, I suspected the EBCM.  I've changed both the front calipers and hoses so I know that's not it.  I'll need to check for a code and go from there, I'm hoping I won't need to completely tear out the master.

Appreciate your thoughts.

[Ronnie]

9 hours ago, fun car guy said:

I'll need to check for a code and go from there,

That would be the next thing I would do.

[Ronnie]

On 12/4/2021 at 5:37 AM, fun car guy said:

Also, why do we need a battery shutoff?   I Just put a trickle charger on it.

I think both work good for different people and for different reasons. I use a battery cutoff because I drive my Reatta several times over the winter and the battery never goes so low that the engine won't start. I find the battery cutoff more convenient than hooking up a trickle charger.  Maybe the battery would go completely dead with the battery cutoff if you left your car sitting all winter without a trickle charger. I don't know.

[Padgett]

I have both. Cutoffs and NOCO Genius 1 "battery maintainers" (several - only trickle charger I've had that stays cool). Sale at Amazon I mentioned is now over. Also have a 55a "dumb" charger for very, very low batteries, a 200A roll around, and a couple of "desulphating" chargers, and a couple of jump boxes. Amazing what you acquire over about a half century, 35 years in the same place.

Oh and a 15w solar charger on the one that is under cover outside.

[fun car guy]

Thanks, guys.  As much as I like my Reatta, hitting one roadblock after another gets frustrating but your help is always appreciated.  

[fun car guy]

In reading my manual for the breaking system (ABS included) I see there is a proportioner valve but it only services the rears so that's not my problem. Maybe I'm just too old school to bother deciphering the codes telling me what I can clearly see with my own eyes, that being there's no flow to the left front wheel as far back as the master so It would seem my problem is within either the ABS module or the master cylinder it's self.  Besides, Given that the system worked before on all four wheels with no pulling but were just weak it's a mystery why this is happening.  Can I assume it's the ABS module as after disconnecting the pipe leading to the front left and seeing absolutely no fluid in spite of pumping the brakes?  I could start there but that would require removing and replacing the entire master which would be very difficult and costly or is it worth it to just replace the ABS module and hope that does the trick.  Is it even possible to replace the ABS module without removing the entire master?

There has to be a simple explanation as I'm sure someone here has had a similar experience!!!

[2seater]

Section 5E-3 states the valve block is replaceable, but it is not itself serviceable. It is in far left field, but it is one of the functions of the ECBM to open and close the six valves in the actual valve block, but that should indicate a code. It also states the left front, right front and rear valve pairs are hydraulicly isolated from each other. I have never looked at these parts in detail but a fast Google search for a Teves II valve block came up with this from a Ford Thunderbird: NEW - OUT OF BOX E9SZ-2C266-A ABS Valve Block 1989-1992 Thunderbird Teves MKII | eBay

 

I am not suggesting this is a compatible part even though Ford and others used the Teves II system. They configured and wired things in their own pattern but it looks like there might be something out there as a replacement. Incidentally, I have found the Volkswagen tutorials on the Teves system to be the most clear and informative.

 

 

[Ronnie]

1 hour ago, 2seater said:

one of the functions of the ECBM to open and close the six valves in the actual valve block, but that should indicate a code.

I agree, and I will say this one last time... I think the brake codes should be checked.

 

I believe if the problem is with the ECBM keeping the valve closed that unplugging it should disable the ABS part of the brake system. Doing that should set the valves to the default position which should open all the time. If you look at the video below, starting a the time of 6 minutes, it shows that each front wheel brake is feed by a separate piston in the master cylinder when you press on the brake pedal - even when the brake pump isn't running. It's possible that the ABS valve is open and the piston for the left front wheel is at fault. Putting a vacuum pump on the outlet where the left front brake line connects might give you an idea of what is going on. Even if the piston can't push fluid through the line a vacuum pump might be able to pull fluid out if the ABS valve isn't blocking the path.

 

In my opinion the easiest way to solve this brake problem is to replace the complete Teves unit and be done with it although it may not be cheap.

 

 

[fun car guy]

True, not cheap and certainly not easy.  I already checked with Jim Finn and he gave me a price for a replacement (used) accumulator or master body at $250.00 each and from what I've seen, the job to replace the master body is a royal pain.  If simply disconnecting the ABS is possible, I'd be happy to live without it and just have normal braking power on all four wheels.  Besides, I already know the valve to the left front is closed as there's nothing coming out even when I press on the brake pedal hard showing the ABS is faulty!  However, If I vacuumed the line and forced fluid out, are you suggesting that would force the valve to open and hopefully solve the problem or would it simply close again once I remove the vacuum pressure? 

If you really think checking for a code will help, I'll check and let you know but I suspect it'll simply indicate a malfunction of the braking system.  BTW, both the red brake light and the white ABS lights come on and don't go out.

Thanks for your thoughts, suggestions and for the link to the video.  The system isn't as simple as I originally thought!

 

[Padgett]

And the codes are often rong. Is more important that whether or not there is a code, mechanical inspection is what is needed. Frayed wheel cable is most common. BTW often the reason for a complex part being NOS is that it didn't work when put on shelf. Return policy or working guarantee is impotant.

[fun car guy]

Thanks again Ronnie for your advice and especially for the video.  It's helped me understand exactly what the problem is with my master.  Clearly, I've decided it's the valve body that's at fault as the valve to the front left is stuck closed and have ordered a good one from Jim Finn.  Of course, I won't be installing it until spring but it's a huge relief off my mind to finally have the answer to the problem.  Once installed, I'll finally have it on the road.

Thanks and best wishes to you and all on the Reatta website for a safe and happy Holiday season!