delco brakes get them working successfully and well

[Vanya]

Hi,

 

I got two GM variants courtesy of an Italian dude on this forum - so I didn't buy from Amazon. Shipping costs shouldn't be so bad though. Furthermore, I believe the part is also available from "GMPartsdirect" but I haven't checked that source out.

 

The accumulator was a direct replacement - no copper washer/interface bolt necessary. I just stole the old rubber O-ring from the original accumulator (bog standard O-ring part really). The only other difference was that it was screwed in with an allen key and not with a (19 mm?) socket as the original part.

[OwenGT3]

It seems they won't ship to outside the USA, the Amazon supplier. Tried to buy but won't accept the UK address.

Now looking for another supplier, or I might go for the P38 version from eBay to cut the hassle of buying overseas.

 

Darren mentioned the P38 accumulator didn't have a shoulder for the o ring seal to press against, so fitted a washer. All the pics I'm viewing in my search show the P38 accumulator with a nut acting as the shoulder for the seal, does this nut have to come off to fit the Lotus unit? It seems that it should screw in with no problems and have a shoulder, or is it the pump unit that lacks the shoulder?

Edited May 15, 2013 by OwenGT3

[dodge1979]

I had already tried to source the unit from USA previously with no result, hence using the P38 unit. Its straight fit the nut it part of the casing and this is how you tighten the unit into the pump housing. The original had a slightly narrower shoulderafter the screw thread, which allowed room for an oring to sit inside the pump body. And be aware that as Vanya states, it is NOT a bog standard o ring part. It HAS to be of EPDM material or it will just disintegrate when in contact with brake fluid and youll end up with pressurised fluid spraying all over the car...

[sailorbob]

I bought a Delco 25528382 accumulator from the 'States without any issues. Try contacting the vendors.

[OwenGT3]

Have found a supplier for the Delco 25528382 in the US, Did live chat and he said they can ship to the UK, works out at $275.50, about £180 roughly, so will order from them.

 

http://www.autopartswarehouse.com/sku/AC_Delco/Brake_Accumulator/AC25528382.html

 

Hopefully this will fix it.

[OwenGT3]

Just made the order. New original AC Delco 25528382 for $278.80 delivered. So a little dearer than one from the UK, but not a modified part, so hopefully no problems fitting.

 

Paid extra for a 4-6 day delivery time, so hopefully week after next, Monday. Having delivered to work address as well, so might not get stung customs or VAT as we buy and sell to US all the time.

Edited May 16, 2013 by OwenGT3

[OwenGT3]

God! My part arrived today from USA, excellent service from Auto Parts Warehouse and Bongo that was used for the international delivery. No customs tax or VAT added either, which I was unsure of, so great result so far, just got to fit it now.

 

Hopefully get it fitted this evening and the problem gone, fingers crossed!

[OwenGT3]

OK, A new switch, a new accumulator, the bill is now up to nearly £500 in new parts and I still have an abs brake problem, the light is still on, it's really is cheesing me off now!

 

Andy C came over to give me a hand, the new accumulator was fitted, bled the system, but the light is still staying on. What the main problem seems to be is the baulk head relay controlling the pump continually

chattering. The brakes are actually the best they have ever been, really good.

 

It seems fitting a new accumulator has improved the pump operating, it is engaging less, but the relay seems to chatter even if it's not operating the pump. I'm unsure where to go now in fixing this problem, I will replace the relay, but don't know if this will sort it.

Edited May 22, 2013 by OwenGT3

[OwenGT3]

Quick test at lunchtime removing the abs fuse has shown the fault is still appearing, so would indicate the abs management ecu is not faulty.

 

I just keep looking at all possibilities, I'm glad I have the manual. 

[sailorbob]

Since you have fitted a pressure switch conversion have you verified that it is operating at the correct pressures? If it is then it could be that the relay is faulty.

[OwenGT3]

It's the pressure switch sold by Steve at Lotus Marques.

 

I did discover today that when the ignition is first switched on, the two relays near the abs management unit were working, then tripping out just as the light came on, so need to investigate further.

[sailorbob]

The solenoid enable relays are de-energised during initialisation if the ABS ecu determines there is a fault worthy of disabling the ABS operation.

[philip600]

It's me again !

After having problems with my ABS light coming on or flashing & my pump running too often I purchased the switches suggested from PVL.

After altering the wiring I switched on the ignition. Obviously the system is de-pressurised, the pump starts to run & after about 20 seconds the handbrake (HB)  tell-tale lamp goes out ( so far so good ) pump continues to run for a further 25 / 30 seconds & shuts off but as soon as it does the HB tell-tale comes on ? ABS light is also stays on ?

Pressing the brake pedal 3 or 4 times brings the pump back on & as soon as it starts the HB lamp goes out, pump runs for 4/5 seconds & as soon as it stops the HB lamp comes back on, any suggestions ?

I've plugged in Espritmon & no warnings lights are on although it states 'ABS disabled' & the ABS light cannot be reset by pressing 't'

Can someone confirm my wiring. There are three wires to the original switch, Black (B), Brown/Pink (NK) & Light green/white (LGW)

I have wired (NK) to the common on the main pressure switch (MPS) & the other connection to (B) to turn the pump on, these seen to work fine.

I have then piggy backed off the common on the MPS to one side of the low pressure switch (LPS) & the other side of the LPS to (LGW)

This seems to work fine initially as it breaks contact once the pumps has been running for 20 seconds but I can't understand why it appears to make contact again once the pump stops ?

Unplugging one of the connections on the LPS does not put off the HB lamp so I don't think it is the switch.

A road test shows the brakes are working well with much more 'bite' than they had before, just the problem with the ABS & HB light ?

Any help would be appreciated.

Many thanks, Phil.

 

 

[ramjet]

Just a quick note, Steve at Lotus Marques in Australia also sells the accumulator. Very reasonable $'s. I got one from him years ago when my pump started running on every pedal press.

 

Another source if you need one.

[sailorbob]

Not knowing how your switches work means I may be wrong but it sounds like you have your wiring incorrectly hooked up. I would expect the following:

BLK to go the common of both switches
BRN/PNK to go to the pump pressure switch
LT GRN/WHT to go to the warning pressure switch.

[philip600]

Hi Derek, Why do things always seem clearer when you've slept on it. I had a thought last night that my wiring was incorrect as you've suggested.

I will alter it as above & report back.

P.S. the main pressure switch makes at 2400psi falling & breaks at 2700psi rising, the low pressure switch breaks at 1800psi rising.

Many thanks again for your help.

Phil.

[sailorbob]

My wiring suggestions will not work for your warning pressure switch. The OE switch opens when the pressure falls below 1800 psi. You'll need to invert the signal so that the ABS ecu and lamp driver module get the correct information.

[philip600]

Sorry my mistake, the new switch does open when the pressure falls below 1800psi the same as the original.

The two switches basically operate the same as the combined original switch.

Phil.

[philip600]

Ok, wiring altered as suggested by Derek in post above & now all working spot on, thanks for confirmation Derek 

Many thanks also to Darren ( dodge1979 ) for putting the effort in to sort the Delco brakes & for spending the time writing it up on here.

I now have brakes that work once again ( still need to replace brake light switch as it's a bit slow sometimes ) all thanks to the help on TLF

Kind regards, Phil.

[PaulEspritGT3]

If anybody would like to replace a failed ABS pressure switch with this two switch solution but doesn't want to do the work Paul Matty Sportscars in Bromsgrove are now offering the fix.

[andydclements]

Based on the experience with OwenGT3's car, I'd say professional work by somebody who has access to a calibrated pressure gauge would be really worth the cost, and given the short time it should take to unscrew the old unit and fit the new ones, that cost should be relatively low.

[markw996]

Hi, I have just bought an S4 Esprit that has a rather 'wooden' feel to the brake pedal, the brakes feel very inefficient and actually quite frightening (wondering if it's going to stop in time when you have to brake hard).

 

Can anyone advise where I could get a suitable pressure gauge and adapters to install into my braking system for an accurate diagnosis of whats on with it?

 

Would the following be suitable, or are there cheaper / better alternatives out there:

 

http://www.ebay.co.uk/itm/Hydraulic-pressure-test-kit-with-2-pressure-gauges-Thi-/380661484358?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item58a1314b46

 

I've been doing a lot of reading but have not done any tests yet as the car is currently garaged a few miles from where I live, but it seemed that the ABS pump was running every time you press the pedal though I don't have any warning lights yet.

 

Thanks,

Mark.

[markw996]

Just to update,

 

1) It takes 36 seconds to fill the accumulator.

 

2) My ABS pump does indeed run every time the pedal is pressed, or occasionaly every second time.

 

3) I can hold the pedal as hard as I can for 3 minutes and it won't come on after the initial first time.

 

I don't think I'm going to be able to diagnose further without building some kind of pressure test rig which is going to be a challenge as I know practically nothing about hydraulics

 

Mark.

[Bibs]

This should be being addressed under your warranty mate...

[markw996]

There is no warranty as such, and even if there was I have no warning lights or fault codes showing.

All I have are exceptionally poor brakes, which I'm sure they would be only too happy to point out is normal for Esprits of this age.

Also it just went through an MOT with no advisories which wouldn't help my argument much.

 

I'd rather fix it myself if it's only going to cost a few hundred pounds to improve things.

 

Thanks,

Mark.

Edited August 8, 2013 by markw996