Brake test results.

[gr8scott]

I 'd just done the recommended 7-step brake test on my 89, then repeated it an hour later to be sure I have the right numbers. Here are the results:

Test 1: 4 sec yellow, 5 sec Red

Test 2: 29 pumps

Test 3: 45 sec (both simultaneous)

Test 4: 52 sec

Test 5: One pump

Test 6: 11/16 inch.

Test 7: Immediate thump.

Not being mechanically proficient, I'm unsure of interpreting the results, but it appears that the accumulator may be nearing the failing point. Your opinions as well as suggestions on what other problems this test may indicate are most welcome.

[Ronnie]

I had similar results with the brake test a couple of months ago and a new accumulator fixed the problem. I believe one pump on test #5 and not having 1/2 inch in test #6 is a good sign the accumulator has gone bad.

Many have had good luck, including myself, with gmpartsdirect.com . Their prices are very reasonable for the part, but the shipping costs are way out of line. However, with that having been said, together the price is still not as much as a dealership.

[Guest wally888]

Previous poster hit the nail on the head!

Replace the Accumulator to avoid the Pump running excessively, then burning out, perhaps resulting in no brakes and a wreck!

[gr8scott]

Thanks. Local Buick dealer quoted me $191 for parts (Accumulator with O-ring) and $212 for labor, which would include flushing the brake fluid. Does that sound about right for this?

[Ronnie]

I paid $131.00 for accumulator, including shipping. Screwed old one off and screwed new one back on in about 15 minutes. Be sure to relieve all pressure in the system before changing. Pumping the brake pedal about 30 or more times with the ignition switch OFF should do it.

Ten dollars should cover the cost of brake fluid to flush the brake system, which should be done.

Instructions for both operations can be found here and in the FSM. How much is your time worth?

[Guest wally888]

Rip off!

[gr8scott]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TDman</div><div class="ubbcode-body">I paid $131.00 for accumulator, including shipping. Screwed old one off and screwed new one back on in about 15 minutes. Be sure to relieve all pressure in the system before changing. Pumping the brake pedal about 30 or more times with the ignition switch OFF should do it.

Instructions for both operations can be found here and in the FSM. How much is your time worth? </div></div>

I haven't been able to come up with a FSM yet, and the only reference I can find to this procedure is the attached paragraph from the online FSM. It looks like a two-step screw-off/screw on operation )after removing the brace that runs across the front of the dash). Is that about it?

[Ronnie]

That's about it. I can offer a few tips that I learned while changing mine.

Mine old one was really tight. There is a hole at the top for using a hex wrench (Allen wrench). I used an allen wrench along with an oil filter wrench around the body of the accumulator for a more even pull on the accumulator. The oil filter wrench was the type with a handle on it that gets tighter as you pull on the handle.

I had a helper trying to hold the part in place that the accumulator screws in to. That part does not seem very sturdy when you pull hard on the accumulator trying to remove it.

Be sure to put a little oil on the new O-ring to lubricate it before installing it.

I didn't tighten the new accumulator nearly as tight as the old one and it didn't leak. Maybe the old one was tight from being on so many years.

Good Luck!

[gr8scott]

Thanks for the pointers, Ron. GMDirect lists the part w/o-ring at $106.93. I'll report back with my experience after I get it and install it.

[Ronnie]

I look forward to hearing if the accumulator corrected the problem.

[Guest whytshdo]

Do you have a part Number for the accumulator??

[Ronnie]

From: GMPartsDirect.com

1 - #25528382 Accumulator - $104.84

Shipping: $23.65

ORDER TOTAL: $131.19

Expensive shipping but overall good price. Best one I could find.

[Guest whytshdo]

Thank you. I'm having problems with their catalog and the number will make it much easier.

[Ronnie]

Order a new O-ring at the same time. I believe the part # is #25528383 but check.

[gr8scott]

I contacted GMPartsDirect to confirm the part numbers. Their reply was:

#25528382 Accumulator

#25528383 O-ring

I just received it this afternoon. It appears that I didn't have to order the separate O-ring because after removing the thread protector cap from the accumulator I found that it comes with one pre-mounted and lubricated. (See attached pic)

Next task: swap it out.

[gr8scott]

I've installed the new accumulator. Unsure about the torque applied, but it's reasonably tight without flattening the O-ring. I the ran the 7-step brake test. Below are the results compared to the results before the accumulator swap out.

------Before------------After

Test1.. 4Y 5R...........6Y 7R

Test2.. 29 sec..........11 sec

Test3.. 45 - 45 sec.....16-16 sec

Test4.. 52 sec..........31 sec

Test5.. 1pump...........1½ - 2 pumps

Test6.. 5/8 inch........7/16 inch

Test7.. OK .............OK

I was unable to detect a slowdown in the speed of the pump as it charged the system, whereas this slow down was clearly audible <span style="font-weight: bold">before</span> the new accumulator was installed. Odd?

I drove the car, let it sit a while then ran the test again with identical results. I see that there is a difference between my results and those listed as average on the Reatta.net Data pages, but need assistance with interpreting the results.

One other thing: holding the part fast that the accumulator mounts onto, I noticed some movement at the point indicated by the arrow. This movement was only there if the part was moved in a slight arc by its other end. The movement is not excessive, and only happens with reasonable force applied, but I thought I'd mention it to see if it indicates anything. As always, your thoughts and input are appreciated.

[Ronnie]

This is what is important.... Do the brakes seem to perform like they should? No warning lights under normal operation? Normal feel when stopping? Good stopping power?

There are some things that can affect your test results such as air in the braking system, variances in the pressure behind the bladder in the accumulator, and the accuracy of the pressure switch that controls when the pump motor cuts off. I would say your test results are in the ball park. If I remember correctly my results did not match those listed at the bottom of the test page but my brakes have worked well since the accumulator was replaced.

If you look back at one of my earlier posts I cautioned you that you might need a helper to hold the part you are pointing to in order to prevent excessive movement when removing the accumulator. I believe it is normal for that part to move when torque is applied.

Do you feel your brakes are now fixed?

[gr8scott]

The brief test drive and several heavy brake applications (on level ground as well as downhill) indicated no problems, and the feedback from the brake pedal didn't seem to have changed. It requires a bit more pressure on the pedal than my other cars, but I think I remember reading here that this is normal for Reattas.