Normal bleed down time for a PM ?

[fc227]

Greeting all,

What is the normal bleed down time for a PM ? My rebuilt PM (Motor pump assembly) after ~ 2 minutes the Motor will come on and run for ~ 3 seconds. (replaced in Jan of this year)

Brake light does not come on , good pedal. I have shut the ignition off after and it's take 12 to 15 pumps on the brakes before the pedal goes hard.

I noticed this the other day when I had the ignition on , engine off work with the Power Logger.

 

[charlief1]

Go hydroboost and forget it Fred. YOu've got an issue for sure.

 

[fc227]

Hi Charlie ,

I was reading a around and Found recycle time to be 2 to 5 minutes (so for now I am OK). Yes, I should have replaced the Whole PM, But If I do , I would most likely go to vacuum or hydro boost.

 

[gn4u2c]

Thats within spec and just fine.best tips for pm is to change the fluid once a yr. Anytime you get even a flash of the brake light time to retest it as the light should never be on.(pressure test) Only right way is to use the gauge setup your mind will play tricks on you and all the misinformation out there is just crazy.the PM is a great system if you know what your doing, hydro boost is not the best setup for these cars either that's why GM got away from it.

 

[fc227]

I'm going to flush it this weekend. Good lord willing it mine be a small piece of debris under the check valve ( I assume there is a check valve in there).


I would have never know , if i was not playing with the power logger and heard it recycling.

 

[pacecarta]

the check is in the master cylinder housing , very important depressurize before removeing the steel line where it goes into the aluminum master , once the line is off look inside the master theres a flare adapter cylinder inside that needs to come out (best way is on a bench with a shot of air through accummulator port ..be careful in the car as brake fluid and paint dont mix ) , there's seal is on the back of the adapter and behind the adapter is a small spring loaded metal disc with tabs on back to keep it straight (doesn't look like much but that's the check valve ) . clean the seal on the adapter and the metal disc and make sure the spring is still a spring , reassemble spring -> disc (flat side out ) -> adapter (seal in) -> metal hose

 

[fc227]

the check is in the master cylinder housing , very important depressurize before removeing the steel line where it goes into the aluminum master , once the line is off look inside the master theres a flare adapter cylinder inside that needs to come out (best way is on a bench with a shot of air through accummulator port ..be careful in the car as brake fluid and paint dont mix ) , there's seal is on the back of the adapter and behind the adapter is a small spring loaded metal disc with tabs on back to keep it straight (doesn't look like much but that's the check valve ) . clean the seal on the adapter and the metal disc and make sure the spring is still a spring , reassemble spring -> disc (flat side out ) -> adapter (seal in) -> metal hose

I knew about the depressurizing , But I did not know about the check valve location or how to clean /check. The flare adapter will come out with a shot of compressed air ? It is not threaded in ?

Thank you