Hi, Is there anyone of you VW gurus, in Sydney (inner west area) willing to have a look at the disc brakes on my 1965 Beetle. They have been converted and using the Rod Penrose conversion kit with new MC and most of the lines replaced as well as new rear drum cylinders and brake fluid reservoir but the pedal still goes flat to the floor even after multiple bleedings. The brakes work when the pedal is flat to the floor but I just can;t get it to be where it should be.

Any assistance or advice would be greatly received.

Cheers in advance

Nick

Has the push rod free play rod been adjusted correctly

Power bleed the system, It will fix the problem if everything else is alright.

Rod Penrose conversion kit with new MC

What size is the bore of the MC and what size are the pistons in calipers

this is Front discs only the rears are still drums ???

The Rod Penrose kit is this one http://rodpenroseracing.com.au/vw-5-x-205-kits/1453-wide-5-5-x-205-front-disc...

The set-up is disc brakes set up front and original drums on back. I have replaced the cylinders in the back drums and also the brake fluid reservoir and all the lines to all brakes except the MC to rear brake area lines. (the lines to the rear brakes from where the original lines come out of the body have been replaced.)

Do you think it is the push rod due to the bore size difference?

The master cylinder that is included in this kit is the Bus master. This has a 22mm bore apparently. The stock Bug master, up until 1964 had a 19mm bore and for 65-66 it had a 17mm bore. I am assuming mine is the 17mm as it is a 1965 1300.

Power bleed the system

Hi, I have already power bled the system and the brake was still pretty much hitting the floor before the calipers stopped the discs and drums rotating.

OK so its 22mm MC which should be good for discs 3mm over stock size 68 and on

check the pushrod free play and make sure it fits the piston correctly

Did you replace all the rubber flex hoses ??

If there is an issue with the front calipers retracting you can fit residual check valves in the lines.

A couple of other things you might want to try Nick is that the bleeder nipples are at the top of the calipers and maybe isolate the front and rear brakes by gently clamping the rubber lines and see what happens

Thanks guys.. I replaced all the hoses to all 4 wheels and the front metal lines as well as the reservoir to MC hose.

I will check the push rod as I get the feeling it is too small at the moment but have never adjusted or replaced one before.

All 4 wheels lock up when brake is flat to the floor I just can't get the brake to work like normal with an inch or so free play before brakes take hold.

I'll try again when I can.

Thanks again for the tips.

The push rod when you press on the brake pedal should have about 20 to 25 mm of free play

You will feel it hitting the piston by hand use a 13mm spanner and some multi grips to adjust
make sure carpet and mats are out of the way

Adjusted the rear shoes up?

Thanks to you all for your advice. This will be my weekend project so if there is anything else I should look at in addition to the above please add it to the list:

The drum shoes have been adjusted as they should so the drum turns by hand when the pedal is not depressed but I can feel the resistance of the shoe on the inner drum.

I will look at the pushrod scenario first and then go from there.

I have 3 weeks before the pink slip becomes a required blue slip instead so I am keen to get this finished.

Thanks again

Hi all,

So I made progress with the brake push rod by adjusting it however it needed adjusting almost all the way to able to have the brake pedal work as it should.

This left it looking quite precarious so I backed it off a little and then started the bleeding scenario again.
I power bled the system all but the new passenger front disc brake bled nicely. This one seems to go on for ages and still has some bubbles in the line.
The pedal now travels almost to the floor again.
The handbrake is nicely adjusted.
The car stops nicely but the pedal is almost to the floor with the push rod pretty much maxed out.

Can you buy longer push rod anywhere as this is a 22mm bore Master cylinder and the pedal and push rod are originals from a 17mm bore MC?

If anyone is in Sydney area and fancies having a crack at this for some $ or beers let me know as I think I am close.

Cheers

You could get some 8mm Booker rod from Bunnings to make a new rod or you could cut down a 8mm bolt and fit inside the piston and have the original rod sit on top of it it carnt fall out will act like a spacer

however something isn't right the original should still fit and be long enough

If your push rod is too short move your pedals closer to the bulkhead, they are adjustable

back off the handbrake and only adjust it after the rear shoes are adjusted properly

So have you found the problem Let us know what happened

Did you solve the problem

are they VW calipers? What size pistons do they use? Ive rub 4 spot Porsche brakes all round with a stock 19 mm MC

Hi Guys,

I haven't completed the task yet but will let you know when I have as you have all been very helpful.

Cheers

Any luck with the Brakes