PM3 acting up. I'm thinking accumulator or pressure switch. Thoughts?

[GOT2B GM]

91 CS International LQ1 with PM3 - 80,xxx kms

 

Ever since a HARD stop (100km/h to 10km/h full braking) on the Gardiner in downtown Toronto on the way to the Autoshow, my PM3 has been acting up.

 

 

When you first apply the brakes (normal pressure application) , everything is normal. After holding that braking pressure for a few seconds as slowing down, the pedal with start clicking away with feedback (similar to ABS engaging), until the pump runs again. Once the pump runs, brakes are fine again.

 

When the pedal is clicking away, pedal becomes harder, and braking power is slightly reduced although it still slows and stops ok.

 

I know the car needs an accumulator regardless (pump has always run on EVERY pedal press, and runs every 15-20 seconds with constant pedal pressure. (has ever since I've owned it - a year)

 

I'm wondering if the accumulator is just degrading more to the point that pressure drops off enough to noticibly affect brake operation between pump runs.

 

But if thats the case, shouldn't the pump just be running more often? Thats what makes the think about the pressure switch being faulty.

 

 

Anyways hope that made some sense.

 

I want to get this taken care of before I go for the brakes and realize I no longer have any.

 

Thanks!!

 

 

And then theres the question, does GM still have accumulators and pressure switches?

 

If they do, I'm gonna buy two of each, for the CS and TGP.

[GOT2B GM]

Oh and I can't tell if the Antilock and brake lights are on, because the fucker I bought the car off of pulled the bulbs.

[CSI_MuNkY]

Oh and I can't tell if the Antilock and brake lights are on, because the fucker I bought the car off of pulled the bulbs.

 

I'm too lazy/busy with homework to come downstairs

 

Install new bulbs?

 

Jamie

[GOT2B GM]

Yeah, I could do that...

[White93z34]

Prior no longer sells ANYTHING PMIII related. They referred me to another company that now rebuilds PMIII units and sells accumulators. I don't know if GM does still, I cannot find a GM part number for a accumulator.

 

Just dug up the paper I wrote it all down on: the company is SIA Electronics and their number is 800-737-0915 I spoke to a guy named Kevin who seemed rather helpful, and quoted me $125 for a new accumulator.

[GOT2B GM]

18013994 accumulator

 

18013988 pressure switch

 

 

according to TPS garage

 

 

 

 

 

 

But that supplier you have there seems to have good prices.

 

Thanks for sharing.

[White93z34]

thanks for those numbers from what I found....

 

18013994 is now superseded by 88927271 - accumulator

 

and

 

18013988 is now superseded by 88927270 - pressure switch

 

I may end up ordering a new accumulator shortly from the local dealer provided I can get it for a good price.

[GOT2B GM]

ahhh very good to know. Thanks