1988 corvette C4 ABS Modulator Valve
Thread Starter
6th Gear
Joined: May 2011
Posts: 6
Likes: 0
1988 corvette C4 ABS Modulator Valve
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
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
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
I hope this helps, and with any luck I'll be able to link to the photo I just uploaded.
Ron
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
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
I hope this helps,
Ron
Thread Starter
6th Gear
Joined: May 2011
Posts: 6
Likes: 0
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
Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
I'd sell it for $100 shipped. Otherwise I'll just keep it around as a spare.
Last edited by 86PACER; Jun 7, 2011 at 12:28 AM.
Thread Starter
6th Gear
Joined: May 2011
Posts: 6
Likes: 0
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.
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Heel & Toe
Joined: Jan 2012
Posts: 19
Likes: 0
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.
1st Gear
Joined: Dec 2012
Posts: 1
Likes: 0
From: Williamsburg VA
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???
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???
Last edited by dsmith1313; Jan 8, 2014 at 04:43 PM.
