Intermittant brakes?? What's the cause?

[ksmmspt]

Hello everyone,

I've got an 87GN with 54K original miles and the powermaster setup. I've owned it since '88 and it has the recalled switch and acc bowl replaced. It is a garage quenn and I take it out for weekly rides. Recently my brakes have been working perfectly along a trip, then I'll have a hard pedal with no brakes along the same trip. It will go from working to not working and back to working in the same trip. I have not seen any brake light illuminate during this time. I was going to get the brake fluid drained and replaced as I am almost positive it is the original stuff!! What could be going on here? Could the old fluid be the problem here or am I looking at deeper issues? What can I or my mechanic check? Thanks for your help!

 

[lazaris]

Check the connector itself for being loose or making bad contact.

 

[regan j]

does the brake warning switch light up when u turn key on??

 

[ksmmspt]

No, the light does not illuminate with key on; however, it does light up when the emergency brake is applied.

 

[ksmmspt]

Lazaris: I actually unplugged the connector and reconnected it prior to my last run through town and the problem still occurred. The connector/connection was very good and tight. I didn't spray it with connector spray or anything like that. I may need to trace down the wiring to see if there is a problem.

 

[ThikStik]

OE fluid!! Mr powermaster no likee that....maybe the acc check valve is stuck. Is fluid dark?

 

[novaderrik]

you have no brakes at all? or just no power assist with a rock hard pedal?
they are two different problems with two different colutions.

 

[1quick6]

I'd start tracing some wires looking for a short, especially since your brake light doesn't pop on when you turn the key on. Definitely service the entire system because if there is one thing that will kill a powermaster system, it's dirty fluid. Do you have the brass proportioning valve on the car?

 

[ksmmspt]

Novaderrick: I have no power assist with the rock hard pedal which is intermittant. I'm getting the system checked and flushed tomorrow. And, yes, the fluid is very dark.

1quick6: If the brass valve came with the car, then it's still on there. The only thing that has been changed is the accumulator bowl and the switch that was recalled. Is there something I can include tomorrow when my mechanic is servicing it?

Thanks guys for the replies! Keep 'em coming and I'll report back tomorrow with the findings.

 

[ksmmspt]

Mechanic drained the fluid today. He said it was extremely scammer (imagine that!) and it took a lot longer than normal due to the consistency of the fluid. He checked the main motor connector and found a loose connector pin (3rd). He adjusted the connector and used contact grease and it should be good to go. Drove great on the way home with no problems.

BTW, for those people who think you should never touch a brake system's fluid if you are not having problems: Be sure to sell your car prior to it being 20+ years old!! Won't make that mistake again.

 

[1quick6]

Good to hear. PM systems are not tolerant of dirty fluid at all. Some people even change the entire quantity of fluid every year just to make sure the system remains healthy. That's probably overkill, but considering the chances of ending up in the trunk of the car in front of you, it's worth the time.