I've seen what's necessary for doing the rear set up from drums but does anyone have detailed info to swap '01 SS front brakes onto my '89 conv?

 

Check out the following threads:

https://www.thirdgen.org/techbb2/sho...hreadid=175533

and

https://www.thirdgen.org/techbb2/sho...hreadid=142115

 

"We're" working on it...


Ed

 

It appears that the set up for the '01 SS front brakes is the same as far as turning the orig '89 rotor down to a hub and fabricating a bracket to hold the caliper.

What about the dimensions for the hub and bracket? Does anyone know so that I can tell the machine shop exactly what needs to be done? And do I need to modify the spindle or buy a new spindle?

Thanks for your help everyone.
Bruce

P.S. I've dropped in the LS1 motor into my conv. What an improvement. Just need to supercharge it when I have more bucks. Cha...Ching!

 

This will probably start a lot of repetion, but the hub is machined to about 5.9", Luke, Alloy, and Todd all mention dimentions.

For other dimentions, please read the other 2 Vette brake threads completely.


Ed

 

Yes, as Ed said, please read the two threads completely through, then ask questions.

I just found a set of 98 4th gen rear brakes a few minutes ago, so hopefully I'l lbe doing the entrie front rear changover at the same time.

The only big thing I'm concerend about is getting the correct master cylinder and prop valve for this setup.

 

Exactly. I assume it will be the same ones as a 1LE system would use, but who knows? That's what I have now and that's what I will use unless someone proves some other combination will perform better.

I'd just use the info on Dan's site:

www.ws6transam.org/fcar.html


Ed

 

I just looked up the part number fro the prop valve on that site, and then went to www.gmpartsdrect.com and it's listed for $48.55. It's part# 14089496-valve assembly.

 

I know the 1LE master cylinder and proportioning valve setup will work for the C4 brakes because they are almost the exact same caliper just a thinner opening for the rotor.

The LS1 brake calipers I will have to do some more research on. Baer now sells brakes that use the LS1 caliper cast or extremely close to it. So I will see what proportioning valve they say to use with there setup and that should answer the proportioning valve question.

 

Yep, that's it, for a pre-'89 car. '89 and up use a different one. I got mine from Dal at VanDevere Olds and it was ~$55 shipped, so it pays to look elsewhere besides GMPD...they rape you on shipping.


Ed

 

sometimes that's the case. i was pricing zq8 rims last fall, and pace performance wanted $599 for a set of 4.

i checked gmpd and they wanted $484 for the set of 4. after shipping, the total would have been $525 to the nearest freight terminal iirc. plus, since i would have been buying from an out of state company, no sales tax on the rims.

if i were to buy them from pace, i would have had to pay sales tax on the rims.

 

Yeah I know they nail you on shipping, but I wanted to take a look and see if it was a good part number, and what the approximate cost would be. Now I have a baseline price when looking for one elsewwhere.

I'll try my local dealer first before going to GM-PD for anything.

In looking at the WS6 site, for the rear disk brakes it refers you to the 1LE front brake page for the master cyinder.

According to the info there, I can use my front disk-rear drum M/C when I change over to the 4th gen rear disk brakes.

Somehow this doesn't seem right to me. Am I wrong in my thinking on this? It seems like I would need a disk-disk M/C when I swap to the rear disks.

 

Nope, Dan's right on the money. Per the GM parts manual, all 1LE cars and all '90-up cars, regardless of disc/disc or disc/drum, use the disc/drum M/C. I'm not an engineer so I don't know why they did it, but that's the way it is. That's why I assumed this swap would require those same parts.


This topic was discussed in depth a year or so ago during the 1LE upgrade onslaught, we beat it to death....


Ed

 

Thanks for all the info. I'll dive into the job within a couple of weeks. I'll do the rears first and then tackle the fronts.
I don't know if the master cylinder from the '01 will work but if I don't need it, that would be great. Less $$$. I realize there may be a need for a proportioning valve even if the newer master cylinder fits or I use the original '89 M/C.
Bruce

 

I've been thinking about this and as I recall, a disk brake M/C has a residual pressure valve to keep the pads from retracting away from the rotor. Drums don't need this, but disks do.

So does the disk-disk prop valve cure this problem? If not it seems like you would need a disk-disk M/C when changing to rear disks.

Update:

Just for grins I called baer and asked about their brake systems for a 3rd gen. I specifically asked about the M/C and prop valve. The told me that you use the stock disk-drum M/C, disable the stock prop valve by removing a spings and a seal, and then put an adjustable prop valve in the rear brake line. He said the adjustable valve takes care of the residual pressure problem. I'm a little unsure of his explanation on this. Can anyone shed some light on this for me?

So, does anyone know exactly what spring and seals we remove to disable the prop valve? I can go get one at a bone yard if necessary and tear it apart to look at, but am hoping someone here knows how to modify the stock prop valve.

I'm picking up my 4th gen rear disk setup today, (got it for $200) and after I get my C4 front brakes on, I would really like to get started on installing the rear disks soon. Real soon!

Now I wish I didn't have a race this weekend

 

I lucked out and got the whole brake set up both front and rear plus the M/C for a trade of a aluminim radiator which cost me $400. Pretty good trade. I got to know the guy who sold me the LS1 and was able to get almost any addtional parts off the SS I needed. What a deal!

Thanks for your reply. I think I'm ready. I'll let you guys know what the result is and post some pics.
Bruce