HELP! DRB Brakes ?

Rob. Smith · #1 (**permalink**) 11-05-2007, 04:22 PM

My mates' cobra is a DRB. It's got SLR 5000 brakes, discs on the front and drums on the back. The problem is the proportioning valve. He had it rebuilt and was told that parts aren't available so they put it back together with "O" rings. It blew out the other day and lost most of the fluid. I showed him the set-up on my RMC. Ford master with built in proportioning valve and sigma booster all operating jag brakes.
My question is...is there any other master cylinder / booster set-up suitable for a DRB with drum / disc arrangement ?
Any advice would be good. Smithy

400TT · #2 (**permalink**) 11-05-2007, 05:01 PM

UC Torana's(definitely later ones) had Master Cylinder with built-in proportioning valve similiar in design to the early Commodores. I'm fairly certain it is a bolt-in fit.

We used that Master Cylinder on our DRB.

SLR5000 brakes, hmm, are they still solid disc rotors and cast iron PBR calipers. Or are they vented rotors & calipers same as HQ.

Either way, both came with PBR cast iron calipers standard(different sizes of course for different rotor sizes). The PBR calipers are known to flex and give poor performance. A good upgrade is the alloy Girlock calipers. For solid rotors these Girlock calipers are found on really late UC Torana's. For HQ style vented rotors look at WB Holden for same style Girlock calipers. Calipers are bolt on, but I think the tube nut on them is metric, so would just have to change or adapt the tube nut.

If it is running sold rotors, then changing to drum stubs & a simple adaptor bracket will get you to HQ rotors and HQ calipers(WB Girlock would be better).

Our DRB had UC Torana master cylinder with integrated proportioning valve. Front drum stub axles with HQ rotors & WB girlock calipers. Worked well.

A few of the later Torana front-end DRB's were using Commodore vented rotors and PBR 2 piston calipers or Skyline calipers.

Very, very few UC Torana's had disc brake rears. These were optioned up SL models(with black detailing) or Torana Sunbird SLX models. So just make sure you get drum master cylinder.

Hope that helps.

boss290cobra · #3 (**permalink**) 11-05-2007, 10:54 PM

hi rob not sure if it helps but my drb is running booster from xd falcon
cheers darrell

Rob. Smith · #4 (**permalink**) 11-06-2007, 06:13 PM

Thanks Craig and Darrell. We discussed both of those options yesterday and only needed to confirm what we had spoken about. My mate is out trying to find out about it today. These messages have said it all !
Thanks very much !

400TT · #5 (**permalink**) 11-06-2007, 06:24 PM

No worries Rob, let us know which way your mate goes. There a lot of old DRBs out there with Torana brakes.

acecob · #6 (**permalink**) 11-08-2007, 12:31 AM

Quote:

Originally Posted by 400TT

No worries Rob, let us know which way your mate goes. There a lot of old DRBs out there with Torana brakes.

Not any more hehehe !

Rob. Smith · #7 (**permalink**) 11-09-2007, 03:03 AM

Sorry about the short reply but the middle of the day is not good for me.
Brads' DRB has solid discs which are soon to be replaced with the Hoppers Stoppers modification, drilled and slotted. I'm not sure if they're ventilated but I guess they are. The callipers are to be alloy (Girlocks) I think. He's looking to get a UC master cylinder so it should be a pretty good set-up. (rear drums though ?)
Any way thats his choice. I will report on the final result and how it performs when it is complete.
Smithy.

400TT · #8 (**permalink**) 11-09-2007, 03:11 AM

Sounds good Rob.

Sounds like the same setup as our old DRB.

They will be vented HQ discs and adaptors required to mount the caliper. Will also be a HQ style caliper, but later Girlock version from last of the old Holdens.