tmechanic Posted May 29, 2022 Share Posted May 29, 2022 Well, it looks like I need to replace my brake pressure switch, the pump doesn't shut off and ends up over filling the reservoir. Where can I get the proper socket to remove the pressure switch? Link to comment Share on other sites More sharing options...
2seater Posted May 29, 2022 Share Posted May 29, 2022 I am a bit confused? If the pump is running, it should be draining the reservoir. Is the fluid level in the reservoir at the proper level when the ignition is off and the brakes are pumped 25 times to release all the fluid in the accumulator? Does the pump ever shut off and do the red and amber brake warning lights go out upon starting? Pull the electrical connector from the pressure switch and check for fluid in the connector indicating it has failed. My experience has been the switch is very reliable unless it is leaking 1 Link to comment Share on other sites More sharing options...
tmechanic Posted May 30, 2022 Topic Author Share Posted May 30, 2022 No fluid in the connector, and after changing the battery the pump finally ran fast enough to pressurize the system, at which point it shut off, like it should. It drew down the reservoir to the MAX FULL line. After driving it and slowing down or stopping about 2 dozen times the power brakes became manual brakes, let the car sit for about an hour and the brakes came back for about 6 or 7 presses of the brake peddle, and it was back to no power. I just replaced the accumulator and relays. It seems that letting it sit overnight will allow it to pressurize the accumulator once, why isn't it coming back on? Link to comment Share on other sites More sharing options...
2seater Posted May 30, 2022 Share Posted May 30, 2022 The fluid reservoir is over full if it is at maximum with the accumulator filled. As mentioned earlier, the fluid level is supposed to be set to the level after the accumulator is emptied by pumping the brakes with the key off up to 25 times and the pedal should go rock hard while doing this. The normal running level in the reservoir is 1/2"-9/16" below the full line. This is with an accumulator in operational shape. If the fluid level doesn't change or changes very little between discharged and fully charged, the accumulator is shot. What are the amber and red brake warning lights doing when the brakes fail? When first started after sitting overnight, both lights should be on until the system is pressurized to 1500-1700 psi at which point both should go out at about the same time. If the antilock system has an error the amber light may stay on. The pump should stop at ~2600psi and restart when the pressure drops to ~2000psi, if the red light comes on before the pump restarts, it is possible the pump motor is weak or suffering from heat. The only way to know for sure if it is the switch or the pump motor is to jump power directly to the pump if you believe it should be running. Link to comment Share on other sites More sharing options...
Padgett Posted May 30, 2022 Share Posted May 30, 2022 I'd probably put a trouble light on the pump power downstream of the switch to see when it is supposed to be turning on. If the light is on (pressure is low) and the pump is getting power, there you are. 1 Link to comment Share on other sites More sharing options...
tmechanic Posted June 4, 2022 Topic Author Share Posted June 4, 2022 Well, after more testing it looks like the pressure switch is working fine, but the pump gives up after turning on 4-5 times. I guess I'll snag the pump off a different master cylinder. 1 Link to comment Share on other sites More sharing options...
Padgett Posted June 5, 2022 Share Posted June 5, 2022 Teves pumps should not be hard to find. There is no substitute for good troubleshooting (and a service manual). Link to comment Share on other sites More sharing options...
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