Greetings FB EK-ers, have a list of questions for those that have had all the experiences.
At this point in my Utes life I have an issue with the rear breaks locking on when I start it up, if I disconnect the vacuum to the booster they are fine but the pedal goes rock hard. I am running a standard Ute diff, with stainless re-sleeved cylinders , a set of UC calipers and disks on a HR moded front end, and the bigger booster (VH40) I think the model is and a UC dual master cylinder as well. Now I have the option to get a HR diff that needs a bit of love for a reasonable price, but a lot of the stuff is missing from it. It has the center, axels, backing plates and cylinders there. Missing are the shoes, and the shoe hardware and drums. Now would my newish EK hardware ( new shoes and drums) fit on the HR Diff using the HR cylinders? Is there something I am missing in this set up causing the issue?
Looking for advice in fixing this issue please, its all ahead full on this before I can start on the sedan at Christmas. All help is welcome with open arms.
Thanks for reading,
Happy days.
Dave G.
HR diff in an EK ute to stop locked on breaks???
HR diff in an EK ute to stop locked on breaks???
Whatever....:(
Re: HR diff in an EK ute to stop locked on breaks???
Was it all working before? Maybe your booster needs some attention - hydroboost in Vic can set it up to the correct spec for your set up - very knowledgeabledave68 wrote:Greetings FB EK-ers, have a list of questions for those that have had all the experiences.
At this point in my Utes life I have an issue with the rear breaks locking on when I start it up, if I disconnect the vacuum to the booster they are fine but the pedal goes rock hard. I am running a standard Ute diff, with stainless re-sleeved cylinders , a set of UC calipers and disks on a HR moded front end, and the bigger booster (VH40) I think the model is and a UC dual master cylinder as well. Now I have the option to get a HR diff that needs a bit of love for a reasonable price, but a lot of the stuff is missing from it. It has the center, axels, backing plates and cylinders there. Missing are the shoes, and the shoe hardware and drums. Now would my newish EK hardware ( new shoes and drums) fit on the HR Diff using the HR cylinders? Is there something I am missing in this set up causing the issue?
Looking for advice in fixing this issue please, its all ahead full on this before I can start on the sedan at Christmas. All help is welcome with open arms.
Thanks for reading,
Happy days.
Dave G.
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You will find me lost somewhere!
Re: HR diff in an EK ute to stop locked on breaks???
Hi Dave,
The ek components won’t fit hr backing plates. You say you are running a dual circuit hydraulic system, but the vh40 booster, being a remote booster can only boost a single circuit. I’m sssuming here that your up master is a 1” diameter unboosted unit and that the no return valve if fitted (drum brakes) has been removed.
A workable setup should be having the vh 40 boosting the front disc circuit, and the original rear brakes running unboosted.
If you were in Adelaide I would suggest you take the car to Power Brakes SA at gillies plains. They have always been very helpful sorting out this sort of thing.
I hope this helps but expect further discussion will ensue.
Cheers
Clay
FB ute fixer upper, EK van on rotisserie
The ek components won’t fit hr backing plates. You say you are running a dual circuit hydraulic system, but the vh40 booster, being a remote booster can only boost a single circuit. I’m sssuming here that your up master is a 1” diameter unboosted unit and that the no return valve if fitted (drum brakes) has been removed.
A workable setup should be having the vh 40 boosting the front disc circuit, and the original rear brakes running unboosted.
If you were in Adelaide I would suggest you take the car to Power Brakes SA at gillies plains. They have always been very helpful sorting out this sort of thing.
I hope this helps but expect further discussion will ensue.
Cheers
Clay
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie
Re: HR diff in an EK ute to stop locked on breaks???
Further discussion will now ensue.
Something doesn't sound right. A UC master cylinder is tandem (dual-circuit), and a VH40 brake booster is designed for single-circuit brake systems. And Torana front discs and EK rear brakes will lead to serious brake proportioning troubles. A few photos will help enormously in figuring out what's going on . . .
You will not be able to use the EK rear axle with front discs - you will have to use an HR rear axle with 9/16" wheel cylinders (see below). Back in the dim dark days, you could fit an HR front suspension and rear axle, pull the check valve out of the original master cylinder, fit a VH40 brake booster in-line, and you'd be set. These days, you can't do a disc brake conversion with single-circuit brakes, so you need a tandem master cylinder with a master-vac servo unit, and then redo all your brake pipes to suit a tandem master cylinder. But you'll still need an HR rear axle.
Your description of the startup behaviour leads me to think that the booster is coming on when you start the engine up. To determine that this is the case (and it shouldn't be), disconnect the inlet brake pipe to the booster, start the engine, and see whether the rear brakes apply. If they do, then the problem's in the booster, not the master cylinder. To confirm, start the motor with the vacuum hose connected. Find the bleed nipple on the booster and undo it. (Might be a good idea to put a length of clear PVC tube on the nipple and into a jar.) If lots of fluid comes out at pressure, and the rear brakes release, then you've found the problem: the booster's applying when it shouldn't, and the hydraulic part will need to be pulled apart. But fixing the booster won't fix the proportioning troubles.
The rear cylinders and shoes for HRs are different if you have front discs: You will need to get a pair of 9/16" bore wheel cylinders and the shoes to go with them. The 9/16" slave cylinders do not use pushrods, and the webbing on the shoes is extended so the end of the wheel cylinder pistons bears directly on the shoe. If you don't have the drums, you'll need to buy HD/HR rear drums (but passenger vehicle, not commercial). No other Holden brake drum will suit.
If you're going to fit an HR rear axle to an EK, you'll find that the rear brake hose is almost, but not quite, long enough. The easiest thing to do here is get a custom hose made, 2" (approx.) longer than the original. Which then leaves the issue of the handbrake cable. The HR handbrake cable is different from the EK one, and the mounting system is different. You can raid an HD or HR for the handbrake cable mounts and weld them to the EK body. The HR handbrake cable is shorter than the EK one, so to make the cable equaliser hook up to the handbrake lever, you'll need to make some extender links out of 25 x 1.6 strap and drill them to suit.
Meanwhile, don't drive the ute . . .
Rob
Something doesn't sound right. A UC master cylinder is tandem (dual-circuit), and a VH40 brake booster is designed for single-circuit brake systems. And Torana front discs and EK rear brakes will lead to serious brake proportioning troubles. A few photos will help enormously in figuring out what's going on . . .
You will not be able to use the EK rear axle with front discs - you will have to use an HR rear axle with 9/16" wheel cylinders (see below). Back in the dim dark days, you could fit an HR front suspension and rear axle, pull the check valve out of the original master cylinder, fit a VH40 brake booster in-line, and you'd be set. These days, you can't do a disc brake conversion with single-circuit brakes, so you need a tandem master cylinder with a master-vac servo unit, and then redo all your brake pipes to suit a tandem master cylinder. But you'll still need an HR rear axle.
Your description of the startup behaviour leads me to think that the booster is coming on when you start the engine up. To determine that this is the case (and it shouldn't be), disconnect the inlet brake pipe to the booster, start the engine, and see whether the rear brakes apply. If they do, then the problem's in the booster, not the master cylinder. To confirm, start the motor with the vacuum hose connected. Find the bleed nipple on the booster and undo it. (Might be a good idea to put a length of clear PVC tube on the nipple and into a jar.) If lots of fluid comes out at pressure, and the rear brakes release, then you've found the problem: the booster's applying when it shouldn't, and the hydraulic part will need to be pulled apart. But fixing the booster won't fix the proportioning troubles.
The rear cylinders and shoes for HRs are different if you have front discs: You will need to get a pair of 9/16" bore wheel cylinders and the shoes to go with them. The 9/16" slave cylinders do not use pushrods, and the webbing on the shoes is extended so the end of the wheel cylinder pistons bears directly on the shoe. If you don't have the drums, you'll need to buy HD/HR rear drums (but passenger vehicle, not commercial). No other Holden brake drum will suit.
If you're going to fit an HR rear axle to an EK, you'll find that the rear brake hose is almost, but not quite, long enough. The easiest thing to do here is get a custom hose made, 2" (approx.) longer than the original. Which then leaves the issue of the handbrake cable. The HR handbrake cable is different from the EK one, and the mounting system is different. You can raid an HD or HR for the handbrake cable mounts and weld them to the EK body. The HR handbrake cable is shorter than the EK one, so to make the cable equaliser hook up to the handbrake lever, you'll need to make some extender links out of 25 x 1.6 strap and drill them to suit.
Meanwhile, don't drive the ute . . .
Rob
Re: HR diff in an EK ute to stop locked on breaks???
Double check that the pushrod that goes from the pedal to in the back of the master cylinder is not over adjusted...
Seen this cause that same problem.
Seen this cause that same problem.
As low as you can get em with rag tyres,primer & dirty big cams!Perfect.
Re: HR diff in an EK ute to stop locked on breaks???
Thank you to all that have advised. I can not access the car until Saturday as it is on the other side of Brisbane. When I can access the car photos will follow. I think I may give this diff( the one with the missing parts) a miss and chase another HR diff. Now there used to be a good break place with a couple of old school guys that knew there sh!t near the Petrie overpass on the north of Bne but they have moved. Does anyone in Bne know where they have gone?
Also now I am chasing another complete diff is there someone who has one and would like to part with it.
I think the problem is with the way the booster is set up and the rear end ( Diff ) So I will try to get it to a good break place and get it sorted after the new diff is installed. And just to add I am not and will not be driving the Ute until the brakes are in full working order.
Thanks again and more to follow.
Dave G.
Also now I am chasing another complete diff is there someone who has one and would like to part with it.
I think the problem is with the way the booster is set up and the rear end ( Diff ) So I will try to get it to a good break place and get it sorted after the new diff is installed. And just to add I am not and will not be driving the Ute until the brakes are in full working order.
Thanks again and more to follow.
Dave G.
Whatever....:(
Re: HR diff in an EK ute to stop locked on breaks???
Sorry I dont agree that you can’t use the original rear brakes. You run the rear brake circuit un-boosted, so the smaller wheel cylinders are not required. Boost the front circuit to the discs only.
FB ute fixer upper, EK van on rotisserie
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie
Re: HR diff in an EK ute to stop locked on breaks???
I didn't think the registration authorities were too keen on having only one circuit boosted . . .
Rob
Rob
Re: HR diff in an EK ute to stop locked on breaks???
Depends fairly heavily on the engineer.
NCOP is largely silent:
When the brake system of an early model vehicle is modified, a dual or split circuit brake system should be fitted. Disc brakes are highly recommended on the front and generally should be power assisted.
Cheers,
Harv
NCOP is largely silent:
When the brake system of an early model vehicle is modified, a dual or split circuit brake system should be fitted. Disc brakes are highly recommended on the front and generally should be power assisted.
Cheers,
Harv
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
Re: HR diff in an EK ute to stop locked on breaks???
Oh boy.!
Every XR XT falcon had dual circuit master cylinder with an inline VH 40 L booster that boosted only the front brakes.
You need the smaller rear wheel cylinders because the front discs combo..just as they did in HR.
Every XR XT falcon had dual circuit master cylinder with an inline VH 40 L booster that boosted only the front brakes.
You need the smaller rear wheel cylinders because the front discs combo..just as they did in HR.
As low as you can get em with rag tyres,primer & dirty big cams!Perfect.
Re: HR diff in an EK ute to stop locked on breaks???
No. HR was single circuit with remote booster affecting front and rear brakes. If you fit disc compatible rear wheel cylinders but only boost the front, the rears won't do hardly anything.
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Sent from my SM-G973F using Tapatalk
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie