Please help...Brake light flashes

[TurboV]

Just had a brake problem present itself this week and I have The Turkey Run this weekend in Daytona Beach. I found the artilcle on Gn/ttype tech about trouble shooting and it seems like its the accumilator bowl.. It is the newer part with the yellow lettering. I pumped the system and bled the brakes and the pedal feels good. Pump seems to come on and shut off as it should but now the brake light comes on when your driving and touch the brake pedal. after driving awhile (Carefully), it stopped coming on. I will Test it again tomorrow and see how it feels and if the light keeps flashing. I Know this brake system has been a big issue for the TR's. My first question is does changing the accumilator sound common? Im limited on funds, have the biggest car show Thanksgiving weekend, and need any parts yesterday....Your advice and insight is much appreciated... Thank You.
P.S. Its an 87 GN that I have redone just about everything. Eng. Trans. Rear. and it makes good HP. Ive only done Pads, Shoes, Ect. to brakes...

 

[TurboV]

The accumilators are $189.00 and I dont want to spend that kind of money if thats not the problem....thanks again.

 

[bigcap]

I kept blowing fuses and bought the Accumulator Bowl that wasn't the solution. I had to buy a new pump off of Brian at G-Body.

 

[1quick6]

If you were blowing fuses, it is almost never the accumulator. The fuse blows because the motor is dying or the windings are wet with brake fluid causing a short.

If the brake light is illuminating, it is usually the accumulator bleeding off pressure when it shouldn't be. The motor has to run more often to keep it charged if it is leaking, so you should notice that. Did you clamp the proportioning valve when you were bleeding the brakes? You might want to check the proportioning valve to make sure the valve isn't popped out requiring a reset. I doubt it is proportioning valve related, but I am just throwing that out there.

Just things to check...

 

[TurboV]

Thanks for the reply. I will check that plunger. I test drove the GN again today (running great and after driving for a while, the light stopped coming on... I didnt mention that the car sits for long periods of time and probably isnt driven enough. When i got the car back in the garage, I turned the car off and back on and the light flashed again...I also did test the fuse and switch and both are good..FYI. thanks.

 

[TurboV]

Ttt.

 

[GullsGN]

Ttt.

It is the accumulator. I have replaced it twice in the last 24 years. As was stated earlier, if the fuse is not blowing it is likely the accumulator. When my light started to come on briefly I waited awhile, a couple of years. Just be careful. If you pop a fuse it takes a LOT of foot pressure to stop.

 

[TurboDave]

If you were blowing fuses, it is almost never the accumulator. The fuse blows because the motor is dying or the windings are wet with brake fluid causing a short.

.

Some good points but not always. I just cured a blowing fuse problem on my 87 with a new pressure switch, and diagnosed the exact same issue (bad switch blowing the fuse) on GNX 405.

The switch is actually a more common issue with the fuse blowing.

 

[TurboBuRick]

Some good points but not always. I just cured a blowing fuse problem on my 87 with a new pressure switch, and diagnosed the exact same issue (bad switch blowing the fuse) on GNX 405.

The switch is actually a more common issue with the fuse blowing.

Hmm, thats interesting Dave.

 

[TRICKSIXPA]

if you used the trouble shooting guide on GNttype it's pretty self explanatory. I did mine last yr yeah it cost $150 to replace the accumulator but it worked. Also while your at it replace the brake fluid to it needs to be changed once it starts showing discoloration. Fluid should be filled about 1 1/2 from the bottom.FYI-If your pressure switch at the top happens to be black replace it all the GM replacement switches were grey.

 

[TurboDave]

Hmm, thats interesting Dave.

Ya, Richard Clark explained the why's and wherefore's while we were troubleshooting GNX405 at the nats. and was explaining how the failiing switch was causing surges and "clicking, on/off" unecessary motor runs etc. the undue current surges were taking out the fuse.

Same thing was happening to my 87 recently. I got lucky and guessed it was the switch and it cured the blowing fuse issue.

 

[HI85WH1]

Yup.. Mine had similar syptoms... pump motor would run,cycle on-off OK, but a little too frequent and the light would flash occasionally. Ultimately, it failed (in traffic of course) and left me stranded in a parking lot until I was able to tap on the motor to get it to run again.

I converted to vacuum brakes. Cant have my wife driving the car and the no brake issue show up on her...

 

[TurboV]

Thank You everyone for all your replies and input...maybe you can post back the best place and price I can purchase a new accumilator. seems like most of our goto Venders are all around $189.00. Does it pay to spend that much money when for $200 more I can get a Vacume conversion kit? I guess it comes down to labor. I drove the GN again this morning, and after a short while, the light stops flashing. Car sits to much... Happy Thanksgiving everyone. Best to your Families...Thanks

 

[1quick6]

You can always test your brake switch with a multimeter. All of the terminals should have continuity to each other. I still think it is the accumulator. I don't know of a cheaper source than what you have seen already. They list for well over $300 at parts stores. Yikes.

 

[chopped39]

The vacuum conversion is cheap replacement. They pop up on here every once in a while for around $150-$200. search it out .The boster and master numbers are on this site somewhere. then go to napa and get new parts.The only problem is the pedal has to be changed. I dumped my power master when I wrecked my car because of failure.When they say hard pedal let me tell you .You aint stopping A lumina stopped me

 

[TurboDave]

You can always test your brake switch with a multimeter. All of the terminals should have continuity to each other. I still think it is the accumulator. I don't know of a cheaper source than what you have seen already. They list for well over $300 at parts stores. Yikes.

True, but the ohmeter test doesn't tell the whole story.

 

[HI85WH1]

The vacuum conversion is cheap replacement. They pop up on here every once in a while for around $150-$200. search it out .The boster and master numbers are on this site somewhere. then go to napa and get new parts.The only problem is the pedal has to be changed. I dumped my power master when I wrecked my car because of failure.When they say hard pedal let me tell you .You aint stopping A lumina stopped me

Order the vacuum block from one of the vendors, then order a rebuilt booster and a NEW master and find a boneyard brake pedal and youre good to go.

Took me 2 hours to do the swap, only because my now fat azz dont fit under the dash like I used to!

I chose to use a second hand booster, but still replaced the master with new... I got the pedal from the same car as the booster and already had the billet vacuum block witht he extra nipple for the vacuum line from one of my local TR buddies.

 

[TurboV]

Thanks for all the replies...Great stuff as usual... I got a hold of a guy here in town that owns 2 GNs and some parts and he may have an accumilator I can put on my GN to see if the light stops flashing when you touch the brake petal. Got to the Car Show (Turkey Run) without an problems today (Fri) and the Central Florida TR guys will be there tomorrow (Sat). I will let you guys know how it goes and turns out. thanks again....Victor.