Brakes

[Vinnie]

Hey Guys
Just wondering if there is such thing as a proportioning valve for brake line pressure. "In a nut shell" i have put in a HR front disc front end and want to control my rear brakes from locking up, i want to retain the original rear end.
Any ideas?
Vin

[Flamed_FE]

Vin

I had this problem and ended up buying the correct brake shoes as the simpliest (and probably cheapest) solution

I will bring the tread to the top of the board

Al

[Vinnie]

Thanks Al
So i presume the correct shoe would have a smaller friction surface area?, or what brake shoe do i buy i.e -is it a HR brake shoe for a FC  or a specially manufactured shoe for this sort of application? or just a trial an error milling operation?
Vin

[Effie C]

Vin
To retain FC brakes at the rear you will have to go the proportioning valve route as the HR style brakes shoes and wheel cylinders will not interchange with FC units.

It is however possible with adaption to fit the HR backing plate and brakes to the FC diff Housing, or fit a EH housing with the HR brakes.

Why keep the FC housing, HR front not standard anymore why not complete the job.

Also the diff centres will interchange between housings

Good Luck
John M

[robbzfc58]

i went thru same procedure.....hr front/fc rear
finished up putting full hr in the back to overcome rear wheels locking              trev

[RET]

Agree with other recent posts here.  There's absolutely no benefit keeping the FC rear end if you've already fitted a HR front end.

cheers
RET

[Vinnie]

Thanks for the advise, i will scratch my head and weight it up
Cheers
Vin

[Vinnie]

Hey

Slept on it!

Maybe in the future, i will do the whole tranny line,(more funds available), but for now i am itching to get my girl  on the road, and mingle with her sisters. ;)
So does any one know what type of proportioning valve could i install?
Would one from a HQ be effective? or is there a aftermarket type?
Vin

[ACE]

Hey Vinnie
A number of years ago i had a FC with a HR Disc front end and the standard FC rear end with the standard brakes. This car did not have a Brake Booster or proportioning valve, did not have rear wheel lockup and passed the N.S.W. RTA pit inspection.
Pedal pressure was about the same as 4 wheel drums.
Regards ACE :D

[Effie C]

Vinnie
Suggest you visit a good brake mob and they will be able to supply,fit and adjust a valve for You.

If you change to HR brakes in the future you will also have to change the back brake line from front to rear, just something else to think about at this point.

Another option to think about is the fitting of a dual master cylinder and only boost the front section with a VH 40 / 44 booster. CRS sell an adaptor to bolt the HQ style dual master cylinder to fire wall.

More to think about but once it is on the road, more than likely won't be changed unless necessary. ::)

John M

[Vinnie]

Thanks again guys,
John what do you mean from front to rear?
Is that refering to the booster?
Vin ???

[Effie C]

G'Day Vin
The brake lines fitted to the HR are smaller then FC lines, I assume since you already have the front disc's fitted that this line has already been changed. The rear line I am talking about goes from the distribution block just above the handbrake pulleys under the drivers floor to the flexible hose at the diff.
The flexible hose for HR's are different to FC and so is the positioning of its connection on the diff.
If changing to HR diff also the handbrake cables are different and mounts on chassis will have to be shifted.
A lot of little dramas but nothing unusual when modifing cars, just part of the fun.
If you have any doubts talk to a good brake mob who has done this before.

Sorry to keep thinking of more things that need to be done, but memory download is slower these days.
John M

[mcl1959]

Vinnie, I really suggest you get the brakes right on your car before cruising.   It is way to easy to lose control of your car when the rear brakes lock up with dire consequences occuring.  I recall a thread a month or so ago with pictures of a massively shunted FC and various people spoke of personal grief situations.
Please dont let yourself become a statistic or your car become scrap metal.
Some hints for HR rear conversion.
Take the handbrake cable ends which lock into the HR backing plate and install them onto the FC outer cables.  Have a new inner cable made to suit the length and install your new custom outer cables onto them.
This allows the handbrake cable to be installed into the original FC fittings and it looks like a factory made one.
Have a new rear brake hose made with a banjo fitting on it rather than straight fitting which allows the brake hose to clear the shock absorber.
I used both these tricks on an FC I have just completed at work with HR front and rear installed along with HQ master cylinder & VH40 remote booster.

Ken

[Vinnie]

Thanks again guys,
Now i can get all the stuff together for the conversion, as not to stop half way to find that i nead to go out and get something.
Cheers Engineers
Vin :)