Another test for a failed Brake System Accumulator

[Guest wally888]

Normally I would be able to confirm or deny that my accumulator has failed on one of my cars. Unfortunately I have only one car here, the other is loaned out, out of town.<BR> My wife reported the brakes were acting funny, a catch, hesitation in the pedal, something.<BR> I put the car through the tests at Reatta.net and all times,pumps etc., seemed w/in tolerance. ( I was a little short of the average, But<BR> I let the system fully charge, engine off/key on. (turned everything off but key so I could hear the pump run). I could apply the brake pedal once and the pump would start to run.<BR> Either the system is not building to it's designed pressure (about 2600psi) or there is no reserve fluid under pressure in the accumulator.<BR> Each owner of 88,89 or 90 might want to repeat this new test!<BR> I think those with proper performing accumulators will be able to apply the brakes several times, before the pump begins to run? Hope a few let me know?<BR> I have edited ,"Take the Brake Tests" topic, this forum, to include this new test.<BR> If you have not given your car these tests, please do, as you may avoid problems in the future and you'll learn some things about your brake system.<P>------------------<BR> <A HREF="http://www.reatta.net" TARGET=_blank>www.reatta.net</A> has supplemental info re.88, 89 and 90 Reatta Brakes.<BR>Please inform me of any new info, info needing editing or errors. A work in progress.

[Guest wally888]

I have put this thread? back on top. Am hoping some one will confirm more than 1 or 2 pumps before Pump starts up? And , maybe some one else, w/ a suspect accumulator or mushy pedal, will identify a bad accumulator?

[Guest]

The pump on my 1989 starts up after only one or two pedal applications. Otherwise, it test normal for Wally's Brake Test.

[Guest]

Wally,<BR>I did your test on my 90 with 41K miles and the pump comes on after two pumps of the pedal. Other test seem normal except it has always seemed to me that the AntiLock and Brake lights stay on a few seconds longer at start up time on the 90 than they did on either of my 89s.<BR>Maybe well get a few more tests and come up with an average here..So far it seems like a couple of pumps will do it.<P>------------------<BR> My Topless Reatta<A HREF="http://hometown.aol.com/drbuch2000/TheReatta.html" TARGET=_blank>http://hometown.aol.com/drbuch2000/TheReatta.html</A><p>[This message has been edited by Dave Buchanan (edited 04-11-2001).]

[Guest rong]

Wally......I also did the test and the pump starts up after 2-3 pumps. Mostly 3. I have replaced both the accumulator and pressure switch. Sounds like this is to be expected; at least so far!

[Richard S]

I too get two pumps, Wally. Another issue might be how long the pump runs. It should only run for a second orr so to rebuild pressure after two pumps. Might be interesting to collect date on how long they run when the system has been fully discharged [20 pumps].

[Guest wally888]

I have ordered a new accumulator.<BR> Will check the system several times before and after installing to see if I can provide more info.

[Guest]

Hello again wally - I have a yellow light on all the time and the red light will come on after about 10 pumps with the key on. The pump runs for a couple seconds with each pedal push. Brakes seem to work very well except no antilock. Relays are okay. I look forward to finding your results with the new accumulator.<BR>

[Guest wally888]

Briefly, as I am somewhat mystified by the results , after installing the new Accumulator.<BR> I have 2 89's, both, now have new Accumulators. (one replaced last year) The hassle, aggrievation and costs are what lead me to this point.(the Brake Article)<BR> Before removing the old Accumulator I ran the tests (5) , several times.<BR>After replacement, I repeated the tests several times. I have not compared the results w/ the norms (averages) established by 20 or more owners who have taken the tests, and reported the results but Note-The 5 tests below are at a post, in Forum, at, "Take The Brake Tests.") There are only 3 tests at reatta.net (not yet updated)As I look at the data below, to edit, all is well, but after it is posted(what you will see) all the figures. etc., run together! Old #'s are L. , new to the R." were for Test and interesting, go figure.<BR> Test 1 Old A.=4 New A.=13<BR> " 2 =33 =13interesting<BR> " 3 =45/45 =15/15 "<BR> " 4 =55 =35 "<BR> " 5 = 1 or 1/2 =3<BR> Undoubtly the Acummulator was bad, think about Test 5! There was no reserve Volumn of fluid! 1/2 pump and the pump ran!<BR> Evidently the longer times, before installing the new Accumulator (Tests 2, 3 and 4, were caused by the pump having to pump longer to fill the entire Accumulator( cracked diaphragm) instead of just the area on one side of the diaphragm against pressure.<BR> All this said, I might have a Pressure Sensor that sends signals at irregular times! <BR> There were clues presented some time ago that I was having an Accumulator failure, I think?<BR>1. When I flushed the brake system, using the on board hydraulics, the flow from the rear bleeders was much slower(not much pressure) than I had expected.<BR>2. Some time ago I suggested , you might be able to identify a bad Accumulator, if, the Reservoir level dropped more than an established average of several cars. We don't yet have an average but: I filled both of my cars Reservoirs, properly to the line.(after pumping to hard pedal) Then turned both keys on. When the pumps had stopped running, I made a grease pencil mark at the new fluid levels. The car w/ the new Accumulator,(was old then) sucked up a lot more fluid! It's Reservoir level was almost 1/2 inch lower than the other car.<BR> Now, both have new Accumulators, they suck up the same amount of fluid. Draw your own conclusions.<BR> I will edit post," Take the Brake Tests", to add test 6. Measurement of difference of fluid level before and after pressurized. Hope youall will provide enough results to establish a good average?<P>------------------<BR> <A HREF="http://www.reatta.net" TARGET=_blank>www.reatta.net</A> has supplemental info re.88, 89 and 90 Reatta Brakes.<BR>Please inform me of any new info, info needing editing or errors. A work in progress.<P>[This message has been edited by wally888 (edited 04-17-2001).]<p>[This message has been edited by wally888 (edited 04-17-2001).]