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Tue Sep 16, 2025 10:53 pm

Hello All.
I have a Manx clone on a ‘61 beetle chassis. Just finished the build last month, but I’ve got a brake problem I have to figure out.
I have EMPI disk brake conversion on all 4 wheels. Replaced the master cylinder to a dual. It also has a proportion valve in the system. It has the stock pedal assembly.
After installing and bleeding everything, all appeared fine until I tried to push it out of the garage. Wouldn’t budge. Did some reading, and one thread suggested increasing the brake pedal play. I did so to the point of at least an 2” play, but it all but took care of the brakes being locked up. However, now the problem is, every time I get in to drive it, I have to pump the pedal to get brakes. Seems to lose pressure everyday.
There are no leaks. I’ve checked every connection.
Anyone have any ideas?

Wed Sep 17, 2025 7:40 am

L8ndeb wrote: Hello All.
I have a Manx clone on a ‘61 beetle chassis. Just finished the build last month, but I’ve got a brake problem I have to figure out.
I have EMPI disk brake conversion on all 4 wheels. Replaced the master cylinder to a dual. It also has a proportion valve in the system. It has the stock pedal assembly.
After installing and bleeding everything, all appeared fine until I tried to push it out of the garage. Wouldn’t budge. Did some reading, and one thread suggested increasing the brake pedal play. I did so to the point of at least an 2” play, but it all but took care of the brakes being locked up. However, now the problem is, every time I get in to drive it, I have to pump the pedal to get brakes. Seems to lose pressure everyday.
There are no leaks. I’ve checked every connection.
Anyone have any ideas?

2 inches of play is way to much.....

Wed Sep 17, 2025 7:40 am

L8ndeb wrote: Hello All.
I have a Manx clone on a ‘61 beetle chassis. Just finished the build last month, but I’ve got a brake problem I have to figure out.
I have EMPI disk brake conversion on all 4 wheels. Replaced the master cylinder to a dual. It also has a proportion valve in the system. It has the stock pedal assembly.
After installing and bleeding everything, all appeared fine until I tried to push it out of the garage. Wouldn’t budge. Did some reading, and one thread suggested increasing the brake pedal play. I did so to the point of at least an 2” play, but it all but took care of the brakes being locked up. However, now the problem is, every time I get in to drive it, I have to pump the pedal to get brakes. Seems to lose pressure everyday.
There are no leaks. I’ve checked every connection.
Anyone have any ideas?

2 inches of play is way to much.....

Wed Sep 17, 2025 9:19 am

Hi Dale and thanks for the info. I knew 2” is WAY to much play, but if I shorten it up, the brakes do not release.
I’m wondering if it’s possible that a dual chamber master cylinder could require a different length push rod? Did VW have different lengths of push rods? Or, (I don’t know the inner workings of a master cylinder), when I reduce the pedal travel, I’m not reducing it enough?
I’ll try setting the play at 5-7 mm and see what happens.
Thanks again for replying and God bless.

Wed Sep 17, 2025 10:32 am

I converted my first buggy, Manx style buggy, from single circuit to dual circuit years ago and did not have to mess with the pushrod. Free play is free play, if you have some it's enough, and more doesn't change anything inside the master cylinder.

That is more of an issue when I set up my Mini-T because the brake pushrod is not stock and about 12 inches long. I have mine set for about maybe 1mm free play at the top of the pedal. It is easier to feel the free play if you pop the pedal cluster spring off the brake pedal to test.

I'm thinking you may still have air in your brakes, or have a bad master cylinder. I have seen new bad ones, and getting all the air out can be difficult depending on the location of the bleeders on your calipers. That part would be for others to help with though as I still run stock drum brakes.

Wed Sep 17, 2025 12:22 pm

EV, thanks for your post. I have read about the caliper bleeding on these EMPI conversions, and actually removed the bottom bolt to swivel them to remove any air.
One thing I wondering…..with these EMPI kits, are they the small or big bore master cylinder plungers? Or it that might be the issue in my case. IDK, just throwing stuff against the wall to see what sticks.

Wed Sep 17, 2025 3:19 pm

Make sure there is not something binding the pedal shaft. If the brakes are sticking on this means the piston is not traveling fully to the rear and uncovering the inlet port which allows the line pressure to fall to zero.
Is the pedal return spring doing the job? Did you refurbish the pedal assy?

Wed Sep 17, 2025 5:41 pm

Ray Jay,

That was my thought as well that the inlet port was not opening. I did add a different clutch pedal that positions the clutch pedal further left. While the assembly was apart, I did clean it up, replaced the brake pedal return spring, and re-installed it.
I will check for smooth movement, and re-adjust the free play based on Dales post.
I’ll hopefully have a positive post to make tomorrow. Thanks to all.

Wed Sep 17, 2025 7:14 pm

Make sure the brake pedal stop is properly adjusted so the brake and clutch pedals are in the same plane. Then adjust the pushrod length.

Wed Sep 17, 2025 9:54 pm

I have the EMPI disks on the front of my buggy. I had the same problem with the pedal going in too far. I rotated the caliper to get the bleed valve at the highest point and re bled the system and it took a LOT of brake fluid more than one small container to get only the front brakes to fully bleed. I would try again with the calipers rotated up to get the brake cylinders full and get all the air out.

Thu Sep 18, 2025 2:58 pm

Was able to do a little work on the brakes fixed issue, and found some things. I noticed the brake and clutch pedals were not on the same plane. Thanks RayJay.

Also noticed the brake stop plate was pushed all the way forward. That can’t be right.
The brake pedal return spring has the looped end obviously goes around the brake pedal. Currently the other end of the spring is mounted under the rear pedal assembly mounting bolt. Wondering if it should be pushed around another half turn so it’s pointing forward, thus producing more return power.
I also adjusted the pedal play to just over 1/4”. Brakes were almost locked. If I turned the adjusting nut the other and increased the free play to where the pedal hit the floor, the brakes COMPLETELY released.
So, tomorrow, I will adjust the stop plate, then reduce the free play, and re-bleed the system.
Thanks again to all for the help and suggestions.

Thu Sep 18, 2025 3:18 pm

I don't know about the return spring, but I know the brakes should work just fine without it. I didn't have one on my first buggy, it had rusted away. I don't have one on the Mini-T, it would scratch up all the paint on the pedal assembly, LOL. The master cylinder should easily be able to return on its own and push the pedal back up in the process. Using both single circuit and dual circuit the master cylinder had no problem doing that. (Oh, if the spring is missing you will want VERY little pedal free play, or else you will hear a lot of rattling.)

This concerns me:
Quote: I noticed the brake and clutch pedals were not on the same plane.
The Beetle has a single stop on the floor to set the pedal return height. I suppose the pedals could be a little different in return height due to manufacturing differences or because the stop was tightened down at a bit of an angle. However, they should be pretty close to the same height. I would carefully look to see if the brake pedal is hanging up on something.

Thu Sep 18, 2025 3:36 pm

I do have the return spring mounted on the brake pedal. I have a VW shop manual for a 1200 (1961-65) and on page R-3, it shows a pedal assembly, with what I believe is the straight part of the return spring pointing forward. So, I will fix that too. (Nothing I like better than removing the pedal assembly mounting bolts.)
Again, thanks to all for their help.

Wed Sep 24, 2025 2:40 pm

Hi all,

Just about ready to re-bleed everything, but first wanted to ask this. I have the EMPI front and rear disk brake conversion installed with the 16-9554 dual circuit master cylinder.
I also have a Wildwood proportioning valve installed as well. Currently the brake pedal goes to the floor, with the adjustment to let the brakes release completely.
I have included a couple of pics to see if you guys can spot anything wrong.
TIA

Wed Sep 24, 2025 2:52 pm

Guys, just noticed one thing. I have the proportioning valve plumbed to the front brakes and not the rear. I reread the instructions for the valve and it says to plumb to the rear brakes. Could this FU cause the issue I’m having?
TIA

Wed Sep 24, 2025 3:02 pm

When I first built my buggy, I also used the empi disc brake kits front and rear, and whatever larger dual circuit master cylinder was available from CB Performance. I never bothered with a proportioning valve.

In all honesty, it made me wonder why you bothered to add complexity to your system.

I have other issues with empi, but the brakes worked while I had them

Paul

Wed Sep 24, 2025 4:19 pm

Slayer,

Wanted a valve to insure the rears wouldn’t lock up in a panic stop. And it was suggested I have one in the system (info that I read). However, my plumbing mistake negated my concern of the rears locking.
I’m sure my issue is a result of something I have missed, or done wrong.

Thu Sep 25, 2025 5:01 am

Yes the proportioning valve should not be in the front according to Willwood. I have an E mail from them somewhere confirming that when that was the topic of discussion on this forum a while back. I also would not put one in the system at all unless there is no other way to balance the braking system. Even then dual master cylinders and a balance bar is a better way to go. I would suggest taking it out until you see a need for it.

As for it causing your problem, I think not. Most likely it is still air in the system somewhere.

I put discs all around on my street Buggy and I have drums all around on my sand rail. Both cars have a slightly higher peddle on the second pump but both have solid brakes on the first pump. If the peddle goes to the floor on the first pump... that is not good.

I had a similar issue when I first put the discs (Porsche 944) on the rear of the street Buggy. It seemed that the dust seals and/or the piston seals on the pistons were pulling the pistons back away from the discs when I let off peddle pressure. I fixed it by putting light springs inside the piston cups to counter the friction of the seals. The other solution would have been to put residual pressure valves in the system but this is working.

I am not sure if the EMPI discs even have dust seals but maybe the piston seals are a bit snug and are retracting the pistons. Can you have someone operate the brake peddle and watch/turn the axle/brake hub by hand and look for a space between the pad and the rotor? Do all 4 as one of my rears did it and the other not so much.

Thu Sep 25, 2025 6:53 am

It seems that a proportioning valve is most often added to the front on a beach buggy, because the front end is so light it tends to lock up first. The proportioning valve creates a percentage drop in braking force on the end it's installed on. Adjustable ones can vary the percentage. Here is a good read on how they work and how to adjust them from Wilwood.

There is one bit from the above article about bleeding the brakes worth noting:
Quote: When bleeding your brakes, it can be helpful to turn the proportioning valve all the way in to make bleeding easier. Make a note of how many rotations it takes to fully in, then adjust back out the same amount when finished with bleeding.

Since you have converted to disc brakes I have no idea what your front/rear brake balance is now, it depends on what kits were used. I know if you use stock drum brakes on a buggy the front wheels lock hopelessly early. With drum brakes the most common fix has been to swap in a smaller bore wheel cylinder into the front, or larger bore wheel cylinder into the rear brakes.

Here is a little bit of information from Strange Engineering about the use of their proportioning valve.

Fri Sep 26, 2025 12:41 pm

Well, I’ve pulled the master cylinder and attempted to disassemble it. I got the first part of the push rod out, but the second half is lodged in there. Not moving at all.
I have gone ahead and ordered another master cylinder. After it’s installed, I’ll get back with the results.