LarryS1340

I bleed my brakes and I notice my right front was not bleeding properly, so I changed the hose. It was not the proplem. I disconnected the hose and no fluid was coming out of the brake line. I found the Modulator valve behind the drivers seat. I searched the internet and can not figure out which one of lines on the valve goes to the right front wheel. Can anyone guide me in the right direction. I am looking for a diagram or somehow to figure out what line to unhook and see if it is clear and if it is I am going to assume it is the Modulator valve itself. Thanks Larry

RonsRed88

I just uploaded a scanned page from my 88 shop manual but the way pictures are handled on this site have changed since the last time I uploaded one and it says something like pending approval. I'll add the link once it's approved. In the meantime according to the diagram if you are standing behind the car and looking at the modulator valve, the line is on the driver's side. There should be 3 lines on the drivers side and they are for the front, one is from the master cylinder and the other 2 are for the left and right sides. The line to the right front brake appears to be in the middle and appears to cross under and then back over the line from the master cylinder which is furthest to the rear. The forward line is to the front left brake.

I hope this helps, and with any luck I'll be able to link to the photo I just uploaded.

Ron

LarryS1340

Thanks Ron I will give it a look tomorrow and get back with you

RonsRed88

The photo has been approved. But I must be stupid tonight because I can't find the codes to embed the picture. So, here's a link to it.

I hope this helps,
Ron

LarryS1340

With Ron's help I disconnected the line that went to the right front, started the car and pressed on the brakes and guess what, nothing came out of the valve. Does anyone know where I can buy or cam I rebuild this valve myself? Thanks again Ron

pmihaltian

Here is the photo you are looking for.

86PACER

If it really is the pump (modulator valve) you're better off just replacing it altogether with a tested used unit than trying to disect yours. I have an extra ABS pump sitting around in case the one in the car goes bad I can just swap it out.

I'd sell it for $100 shipped. Otherwise I'll just keep it around as a spare.

LarryS1340

That sounds like a good price as long as it works properly. I am convinced it is the modulator valve. I have the numbers off the valve and I will get back to with them to make sure it is the right one. 88 corvette convertible. Thanks I will get back to you.

chamilton67

Hey I have a 1988 Convertible that has the very same problem and was wondering if the ABS module was the fix or if it was something else? This car has been sitting for 1 1/2 yrs after the previous owner was killed in a motorcycle accident.

LarryS1340

I need to thank for the valve that was sent. the anti lock did not work but it reverted back to power brakes. Its not 100% but it worked alot better than it was.

dsmith1313

Since the 1989 C4 ABS Modulator Valve is not available new or rebuilt by companies; no availability of junk yard units; none available from other owners...has anyone figured out how to rebuild the ABS Modulator Valve or is there a way to bypass the ABS Modulator Valve and rely on a standard braking setup.

An e-Bay seller responded to an e-Mail I sent him. He stated that the problem I am having after installation of front calipers, brake pads and hoses is that there is a problem with the brakes having not been bled correctly and in the right order. Right now the right front has the brake dragging (not totally releasing from the rotor), therfore getting hot, smelling of burning pad and I fear might be possibly warping the new rotor.

What is the proper way and order to bleed the system correctly???