Hi,

I've swapped my rear drums in my 87 IROC over to Ed's 12" disc setup and am experiencing dire, almost non existent, performance from the brakes. I'm wondering if this is down to the proportioning valve still being for the drums? From speaking to Ed I wasn't sure if I needed to swap it over as when ordering the kit he said if he had one he would include it although I probably wouldn't need it.

I've attached a picture of the part I have. The numbers on it read:

NB 14 KH 1479

and

0025 26751

The handbrake is also pathetic but at this stage I need to get the fot brakes working as a main priority to get it through UK safety testing.

Thanks,

 

I'd say it's more of a bleeding problem. As I've read, the drum prop valve actually sends too much pressure to disc brakes - folks swap them out so that the rears don't lock too quickly. Start at pass rear, then do driver rear, then pass front, then driver front. Bleed until it hurts, then bleed some more.

 

Though the drum valve will work (or should), for the best brake performance, using the valve with the correct bias is the best bet. There are valves for disc/drum, standard disc/disc and 1LE disc/disc.

JamesC

 

Problem with the rear drum prop is its designed to hold a bit of brake PSI in the line so they work quicker. Which should have them draggin a little bit???

[Been down a road of bad brakes for a few years now, all new parts n gallons of fluid changes all new but hard line hasn't changed a thing. Like standing on a rock.]

 

Can anyone confirm if that is the correct prop valve? I'm going to swap it out and check the master cylinder at the same time to see if there is anything untowards in there.


Gumby,

Do your brakes work and it's just that they have a hard pedal or are they completley crap?

 

I have the drum disc conversion kit from hawks (not installed yet).
The calippers are not identical, one calipper is missing the return springs, one caliper cable bracket L is platet the R not, rotors are expensive bear's 12" (useless over here), no hard lines.

This should already cheer you up.

I asked and payd for a 1LE prop valve too. They sent me a 91-92 ILE valve with # MB 9 KH 2171 on it.
I really hope it is a 1LE combination valve.

From experience I know the disc hand brake is ridicoulous compared to the drum hand brake.

 

rock auto list a disc disc on their site.


My brakes are like manual brakes, gotta lean on it hard to stop. If it wasnt a stick id be in big trouble. But panic stops still suck like scooty puff jr. Even more so since my right leg is about half strength still being down for a few month with some wild never pain. So its no pleasure to have to lean on it at times.

 

First-design 1LE.

JamesC