Stiff Brakes

Ok, I got a '90 Reatta with stiff brake pedal that is very slow to stop/has very low braking power.

Has ABS and I am have read that the ABS Accumulator could be the culprit. Is there any that could tell me how I could verify this. Also the ABS Accumulator is the round ball looking thing next to the brake master cylinder, right?

Thanks for all your help!!!

Scott,

Get yourself to www.reatta.net

Left hand Menu "Brakes" and follow the instructions to take the "Brake Test"

This Teves ABS brake System, at least I think so, is a reliable system. It needs clean brake fluid to protect it internally so it is now accepted practice to flush the system-this is common with hydraulic systems and since brake systems have no capability to filter the fluid, flushing to remove water content and crud is the ticket.

Flushing though will not fix your complaint, take the test, follow the instructions carefully and post your results back here. Wally888 has developed this test program over several years and it appears very reliable in highliting system problems.

Something is wrong in your boost circuit and you should have constant red and yellow lights on your dash. While the accumulator can contribute to this, it is unlikely that it is your root cause.

Has this been a problem for a long time or did it just start?

It just started, both the ABS and Brake lights are on. I found the brake fluid low, so I pumped the brakes 25 times and it was still low so I added some fluid, to no avail. I'll go through the tests at reatta.net and let you know what I find.

Don't think the tests will help since you evidently have a failure. First and easiest thing to do is to R&R the pump relay since a common problem but sounds like either the pump is not running at all (brakes will be "both feet on pedal and puch very hard") or turning off too soon (not quite that bad) but is going to take some troubleshooting.

We just went through the whole proceedure with a gentleman who had a bad pressure switch so might want to review that thread.

Look here.

The pump is continually running with Key On Engine Off. At least it sounds like it. It has this buzzing noise at the master cylinder area and it never goes off. I also pulled the codes. Codes 21(Main Valve), 31(LF WSS), 47(Two Sensors (Rear)), and 76(RF WSS) were stored.

Those codes pretty much cover everything but codes relate to the ABS, not the boost circuit. May be best to invest in a PRIOR remamufactured system.

Call on a PRIOR system and they said it would cost around $600-700. I don't really care if the ABS system works or not, I just want the brakes to work.

Do you think the accumulator could be the problem? or not likely?

By the way, thanks for your help.

Pump running when key is on but no build up of pressure in system(both lights on)= internal or external leak.

No external leak=internal leak. (Excluding the possibility the Pump is running but not pumping!) 1 st. thing to check. Also maybe Pump is not receiving fluid to actually pump. 2 nd. check.

Probably trash in the Main Valve or one of the 3 electrically controlled Servo Valves. Complete flush might clear trash?? 3rd. step.

Note: I am no whiz at reading the electrical circuits i.e., from EBCM to the Servos and Main Valve. But I suppose the EBCM could be at fault by erronously sending a signal to the Main Valve or a Servo to stay open? (These signals may pass through the BCM?) I think the Main Valve and Servos are held in the proper position by springs.

Hope someone will provide you more info re. a possible Electrical problem. You might disconnect all terminals to these, clean, inspect and reattach.

As stated above , you have a problem(s) outside the anti-lock brakes. Maybe more than one problem.

The codes you found at ALDL, were they history codes, if not, clear them, then recheck.

After reading I add:

Perhaps the sequence of diagnosis should be: Turn everything off but key on=pump runs-can you hear a whine, hiss similar to fluid going through a small opening, a possible internal leak? (5,000psi actually screams).

1 Clear codes-recheck.

2 Replace both or switch relays

Then go to steps above.

While a bad accumuator can accentuate other issues, even with a bad one within a minute of turning the key on, both lights should go out and you should have at least one powered stop. At a minimum, just the red light should go out and same-same.

ABS (yellow light) really is independant from boost (red light) other than if the red light is on (insufficient boost), the yellow will come on to show that the ABS is disabled because of the low boost.

Real answer is with guage but if pump is pumping (can whine without turning and turn without pumping if bad), the red light should go out and again you should have at least one boosted stop.

Now it is possible that something in the ABS is failed open but usually that results in odd feelings like a brake pedal that pushes back at you.

If all else fails a couple of people have replaced the TEVES with a conventional Riviera power brake but this requires running an additional brake line to the back to work properly. Other options are possible but untried.

About two years ago someone documented the entire conversion process so is in the archive somewhere...

I think this is the thread Padgett is referring to:

Part one...

Part two...

Part final.

Looks like quite a job.

Consider this about changing to a NON-Teves System

1. The standard brake system/ master cylinder on similar GM cars (Toronado Riviera ) were at there best underbraked. I have spent hundreds trying to make the brake work well on a Toronado and it was still no where as good as a Reatta with stock System.

It will cost more to replace the Teves system then fix it.

2 . The value of your your car will go down.

3. If you screw up you die.

I would try the the accumulator and relays and the brake flush. You will need to do it anyway.

I have Relay Cheap $10 for 3 Shipping included. email me alankshelby@qwest.net

Could the fluid being real low cause some air to be trapped in the system? It was way below the seam in the Reservoir.

Also performed code 21 trouble tree, turns out to be intermintant.

How would I check to see if the pump is actually pumping fluid?

I didn't hear a whine from the brakes system, just a constant buzzing from the motor.

Thats it for now, I have to go quick.

I hate replacing parts...without knowing for sure. Thanks again.

OK the system definately has low brake fluid pressure.

The data from the sensor reads Low, when I disconnect the sensor it reads high and the motor stops. So I know the sensor is working.

I also pulled a code B482 whick basically says that the pressure is constantly low.