88 Buick reatta brake problems

Last night driving home my brakes went from power brakes to where I had to stand on the pedal to stop. Does anyone have any ideas ?

Thanks

Andy

The problem is most likely (1) the accumulator, (2) bad pressure sw (3) bad pump (4) relay

You can do a Brake search here or go to www.reattaowner.com or www.reatta.net

There are some easy test that will isolate the problem.

Barney,

Thank you. I'm a snow bird currently in Florida and I left my owners manual in R.I. I know what the accumulator is but do you have a diagram showing the pressure switch, pump and relay ?

After you register at reatta.net for access to the documentation area there is a 25 MB .pdf file "Teves Mark II ABS Operation". Since you are posting here, you can download that.

ps the entire documentation set including the parts manuals and service manuals fits on a 2GB microSD card. Don't leave home without it.

I started doing some research on Reatta. net and Reatta regarding my brake situation. Barney suggested 4 things to check, the relay, the accumulator, pressure switch and the motor. I found the accumulator check procedure, turn the key to on and wait for the pump to shut off, it doesn't start. Pump the petal to hear the pump start. The pump does not start. I have my wife turn the key to on whilc I have my hand on the motor and I don't feel anything. Is there a way to test the motor ? Can I feed 12 volts to the connection on the front of the pump ? If the motor is good does this mean its the pressure switch ?

Any help is appreciated.

It would be better if you unplug the motor and test the connections with a meter. If you have at least 12 volts here the motor is likely bad. I got a motor and pump assembley from Jim Finn. My motor was good on mine but would not build pressure.

Just tested the plug, I don't have a meter but have a light tester, connect to the battery the light comes on. Plug the tester in to the 2 wire connection at the front of the motor and the light does not come on. This plug has a pink wire with a black stripe and a black wire. Is ther supposed to be power full time going to the motor ? The key was in the ON Position.

The motor should run if you apply 12 volts to the pink wire with the black stripe. If the pump will not run when applying 12 volts you will need a pump motor. Check to be sure it is getting a good ground on the black wire.

If the motor runs when you do that the problem could be a bad brake pump relay or the fuse that powers it. OR the pressure switch could be bad that triggers the brake pump relay. Take it one step at a time, beginning with testing to see if the pump will run, and you will soon discover your problem.

The pump doesn't run all the time. It only runs when the pressure switch senses pressure in the system is low. If the car has been sitting for an extended period the pump should run as soon as you turn on the ignition switch.

Ronnie,

Thank you. I just put power to the pink wire with the black stripe. My resources are limited so I used my light tester to pierce the wire with the pointed end with a wire on the aligator clamp with the other end of the wire tighted under my alternator hot wire. How can I check if the black wire has a good ground ?

I have already changed the relay and checked the fuse. The relay is the one in the middle on the fire wall correct ? That's the information I got from one of the reatta web sites.

Andy

I'm not sure I understand how you are using the test light but if you are passing 12 volts through the light to power the pump it will not work. The light will act as a resistor and will not allow enough current to flow to power the pump.

It is uncommon for the ground on the pump to be the problem. With your limited tools you should concentrate on getting power to the pump first.

You can't really count on the brake relay being the middle one. Sometimes the positions of the relays on the firewall will get swapped at some point. The brake pump relay is the one that has 4 wires (pink/black - gray/red - red - brown) going to it.

Use you test light to check the red wire, and the brown wire, going to the relay to make sure they have 12 volts on them (key on).

Then if you can, check the Gray/Red wire to see if it is supplying a ground (though the pressure switch) to the relay to pick it up. Really you need a meter to do it properly but... you can check it with your test light if you connect it to a the positive side of the battery and use the probe to test the Gray/Red wire. If the Gray/Red wire is grounded (through the pressure switch) the test light should come on.

Report back here what you find.

Be safe and don't short anything out. If you don't feel comfortable doing the test I describe you might need to have a mechanic look at it for you.

Edited February 6, 2015 by Ronnie (see edit history)

Is sounding like a pressure switch issue. Were you able to download the Teves section (5E) from the service manual ? If so you need to follow chart D-1, Pump does not run. Really need a DVM to troubleshoot. Check if there is a Harbor Freight near you (are many in Florida), they have several inexpensive ones and are usually on sale.

Here is the latest, I bought some wire connectors to power the motor. The motor runs with power. I checked the motor plug with my test light and the light does not go on. I bought a cheap volt meter at Harbor Freight, connected it to the battery, it shows 12V. I put the meter on the motor plug no reading other than zero.

I checked the relay, Key on, red and brown has power. I connected my test light to the power on the altenator with the allagitor clip, I grounded the other end of the test light on the engine block ground, the light comes on. I test the pink w/ black and the gray w/ red wire and can't get the light to come on.

The amber and bed brake lights come on withthe key on for a short period of time.

I noticed the realys are dripping a black tar, I unpluged the two break relays and the black tar is on the conncetors, I'm not sure if this is a dielectric material or it may be the sealer under the plug used for weather proofing the relay plug melting out.

I bought some contact cleaner cleaned them off and retested the wires at the relay. I'm using the ice pick end of the light tester coming from the botton of the plug to pick up the power and grounds.

I did go to reatta.net to download the Teves manual 38 pgs. but I did not see Page or section 5E or chart D-1. I'm still searching all these sites to learn more about this break system. Looks complicated when it's the firs time seeing it.

You may choose to use Padgett's instructions but I will try to help anyway.

You have proved that you have power going to the relay on the Brown and Red wire. I assume you have tried another brake pump relay and know that it is good? If you don't know it is good replace it before continuing.

If you are certain the relay is good it sounds like the pressure switch is bad. To test to see if the switch is the problem, disconnect the connector from the brake pressure switch.

Make a jumper from a short piece of wire and insert it into the connector terminals for the black wire and the Gray/Red wire. Then see if the pump starts when you turn on the ignition switch. Don't let it run longer than a few seconds if it starts. Without the pressure switch connected it could damage the brake system by building too much pressure. If the pump runs with the jumper in place the pressure switch is most likely bad.

If there is any brake fluid inside the connector that you removed from the switch it is bad and you will need to replace it. Pressure switches are available in the Reatta Store.

Sounds like you've got it down to the relay or pressure switch.

I'm thinking it's probably the relay but to confirm it use your voltmeter to confirm the voltage on the gray / red wire on the relay. You said with the key on you have 12 volts on the brown wire. The pressure switch should ground the relay coil thru that gray / red wire to trip the relay and turn the pump on. So if there is voltage on that wire the pressure switch is bad. If there isn't, then the switch is grounding the relay and it should switch the 12 volts from the red wire where you have confirmed it, to the pink / black wire that runs the pump. So if you don't have voltage on the gray /red wire or the pink / black wire, your relay is bad. If its on the gray / black wire, your pressure switch is bad.

Jumper wires completed, I connected it to the pins on the pressure switch for the black and grey/red wire. I turned the key on and put the wire ends, one on the hot side of the alternator and the other on the ground. The pump did not start.

I took the relay from my fuel pump and put it on the brake relay connection and have the same results.

Jumper wires completed, I connected it to the pins on the pressure switch for the black and grey/red wire. I turned the key on and put the wire ends, one on the hot side of the alternator and the other on the ground. The pump did not start.

I took the relay from my fuel pump and put it on the brake relay connection and have the same results.

I'm sorry that I was not able to help you solve your problem. It seems you and I are not on the same page. There are many people here that are familiar with the Teves system. I'm sure they will chime in and offer the help you need.

Just to make sure I was powering the correct side I inserted probes into the pressure switch plug where the black and grey/ red wire are and still no response from the motor.

Ronnie,

Thanks for your help. I just confirmed with the volt meter I have 11 volts at the grey/ red wire. It looks like the pressure swith is the culprit. Any idea wher to purchase the special tool to remove this and the cost ?

Thanks Andy

Yes, you're probably correct. You can prove it by using one of your new wires to ground that gray / red wire with the key on to see if the pump runs then like the pressure switch should be doing if it was working.

Most of us pick up a cheap set of plumbers sink basin wrench sets at HF or a hardware store and use the one that fits the best to crack the switch loose. The correct thin wall socket is hard to find or make and expensive.

http://www.harborfreight.com/shower-valve-socket-wrench-set-96322.html

Dear Mc_Reatta,

Thank you. I just confirmed if I ground the gray/red wire the motor does come on. This is what Ronnie was telling me but I read the procedue incorectly, my fault. I ran a jumper wire from the gray/red to the black as described by Ronnie and the motor came on. Thanks for the tip for the thin wall socket set at HF.

when I change the pressure swithch will I have to bleed the system at all 4 wheels or will it purge it's self as it pumps back into the reservoir ?

Thank you very much .

Andy

No bleeding of fluid should be needed anywhere. Just in case, depress the brake pedal a few times to bleed off any pressure that might be in the accumulator. Normally you would have to do that about 25 times, but since your pump hasn't been running, doubt there is any pressure built up you have to relieve.

After switch is replaced and pump is working, you might have to prime the pump if is running but it doesn't build pressure to shut off. ROJ has procedure for this in case you need it but doubt you will.

If I recall, there is some slop using the closest plumber's socket (more than you'd like,) but it will crack the switch loose. Once loosened, it should turn easily by hand to remove it and start the new one on. You don't need to super torque the new one on either. Don't know if there is a torque spec out there for this switch. Also, the rod that comes with the sockets won't work since the hole isn't far enough away to make it useable. I used a large cresent wrench on the other end of the socket and had plenty of oomph to break it free.

Mc_Reatta,

Thanks for the info. I will need to borrow a cresent wrench, I don't have one this big. I tried to use the rod and there is not enough leverage. Is it safe to apply the extra oomph with the unit assembled to the mastercylinder or should I remove the assembly and put it in a vice ?

Thanks

Andy

You can do it on the car. The switch, pump and accumulator pod is mounted to the rest of the MC with a rubber shock mount to keep noise and vibration down. This lets it rock when you apply pressure to the socket. Believe I used one hand to apply opposite torque to the pod when pushing on the wrench to stabilize it. A helper would come in handy too if you have one.

if all else fails, you can remove the pod from the MC and put in a vise, but you will then have pulled the fluid lines from the unit and have fluid draining out of the reservoir and air in the high pressure line so you will definitely have to prime the pump after you reassemble. No need to make added work unless you have too which is doubtful.

Mc_Reatta,

I tried to break loose the pressure switch as mounted on the MC. I applied lots of pressure, I wasn't comfortable as I could not get it to break loose. I removed one of the mounting bolts from the rubber shock and also used a cresent wrench to hold it in place whild I used another cresent wrench to remove the pressure switch. I was able to get it broken loose applying

opposite force. All I need to do is wait for the replacement to come in the mail as I have an entire assembly from a parts car in R.I. I'm glad I don't have to blead out any air.

Thanks for your help, I really apprreciate it.

Andy

I received my spare pressure swith from a donor car in the mail and put it in. It does not start the motor to increase the pressure. I assumed it was sitting too long and may be siezed up so I bought a new one from the Reatta store. I Just put that one in and the motor still does not start. New Brake relay, and when I jump the red/grey wire to the black the pump starts. Does anyone have any ideas ?

Thanks

Andy