Calling All Brake Gurus

[paulob1]

Thanks for that, I have just rebuilt the front end no leaks and pads and brakes all good, all new poly bushes front and rear, it did this before I had the rebuild so all of the more obvious issues have been addressed.  

 

It only happens when the abs starts pumping, it sort of releases the brakes for a split second and I seem to have no brakes then it seems to apply it more to the off side brake than the near side brake, so pulling me to the right violently at speed.....would that relate to a pressure switch on that wheel...or a cable or something...

 

I have all the leads and programs i will take another look and see what it tells me...

[paulob1]

okay its the sensor on the near side wheel, it is all broken up and not reading properly...getting one ordered and will be back on for next week...whoo hoo, will have goodish brakes..

 

Has anyone upgraded to 6 pots at all...is it worth the hassle.../cost...

[paulob1]

nope its something else, the car has an abs problem, when the abs is off the brakes work fine, no pulling no odd sensations and no problem with pulling right.  with the abs on its night mare time, ie i get heavy unloading of the brakes as if they have come off completely and it pulls to one side usually to the right as if she has been sent there in a hurry, very dangerous.  I am nervous to leave the ABS of all the time but think this is my only choice....is it likely that its a weak pump or is the the ABS unit itself...any ideas...it makes the car undriveable to be honest...

[fflyingdog]

Can you read any error codes off the abs ecu? Sounds as if its commanding one side to release,also (stupid question) but you have checked all the speed sensors are good/wiring etc?

[paulob1]

yes thats what it feels like to me...i have not bothered with the ECU error codes, but will get Dave to have another look, one of the sensors was damaged and we thought that would solve the problem but it has not....

[Chillidoggy]

Any update on this, Paul?

[Dean Henning]

well it May 2020, and I need a ABS High temp switch!!! I have read all the post...and has anyone come up with a replacement switch for this GM Part # 88927270. Regards Dean South Florida USA

[ramjet]

There is an option available from Lotus Marques in Victoria, Australia.

I believe someone on here also had found an option. If you search in here you may find something.

[DigiTiki]

Lotus Marques does in fact make a direct replacement for the pressure switch.  Its pretty simple to install and I'm not a mechanic by any stretch.  I also replaced my accumulator tank.  But my system is still not pressurizing properly.  I hear the accumulator motor running at every press--which it is not supposed to do.  So there isn't sufficient pressure building or not being registered.  No leaks so Its not due to fluid loss.  I'm lost.  Anyone have any other possible reasons for the ABS warning light.  Its solid lit all the time on my dash.

[Barrykearley]

Have you bled the master unit as per the instructions - you even need to do the hidden nipple that’s really hard to get to. Any air in there and it won’t pressurise properly. I did mention this on the other post a day or so ago.

[DigiTiki]

Berry, You have given my my marching orders.  Im gonna tackle this next.  What instructions are you referring to?  My Lotus Marques instructions don't mention bleeding the master cylinder.   Or at least that I noticed LOL.  I've been known to miss a thing or two here and there. 

[Barrykearley]

It’s all contained within the service manual section for the delco brakes.

[sailorbob]

Bear in mind if you are following the brake bleeding procedure in Service Notes Section JF that it is written for a LHD vehicle and the order of bleeding the calipers and isolation valves is different for a RHD vehicle.

[ramjet]

On 22/07/2021 at 11:53, DigiTiki said:

Berry, You have given my my marching orders.  Im gonna tackle this next.  What instructions are you referring to?  My Lotus Marques instructions don't mention bleeding the master cylinder.   Or at least that I noticed LOL.  I've been known to miss a thing or two here and there. 

I would also recommend giving Steve a call or email at Lotus Marques. He would be only too willing to assist.