Brake Bleeding Mystery

[gatordub]

Hey everyone!

I'm having a real head scratcher with my 67 Ghia brakes and wanted to get your feedback.

I've had my car for 2 years. Prior to that it sat for at least 4-5 years.
About a year ago I replaced the rear brake cylinders, shoes, hardware, master cylinder, all hard lines(front and back) except the main one, and all soft lines (front and back). Basically everything but the main brake line from the MC to the T in the back and the front calipers and discs.

A few months ago I ordered this kit from CIP1.
It's EMPI made calipers, rotors, and FAG bearings/races.
https://www2.cip1.com/acc-c10-4124/

After installing this kit I cannot maintain a solid brake pedal.
I have tried the two person pump, gravity bled, etc. I finally broke down and bought a Motive pressure bleeder. I have gone through 4-5 quarts of brake fluid and have even tried holding the caliper above the rotor to get all of the air out. There are no leaks that I can find and the rubber lines are fairly new and seem to be fine. Rears are fully adjusted.

I am stumped.
The pedal will feel hard but as soon as I go for a drive after a couple of blocks the pedal gets spongy. I get to a point where it seems like the discs are dragging and I have to pump several times to reset them.

Should I try cleaning up and reinstalling the old varga calipers?
Have I damaged the new (less than 2 year) "European made" master cylinder?

[jeffrey8164]

I’m going to blame the Empi calipers. Full disclosure: I really dislike their products and have since the late 80’s.
That being said, there is this residual valve
https://vwparts.aircooled.net/Residual-Pressure-Va...-valve.htm
Might help? Kind of doubt it though.

I’d slap your old calipers back on and see if the problem goes away. Unless, of course, those are frozen or leaking.

I put new Vargas on mine in 2019.
I’m pretty sure good Varga/TRW calipers are still available.
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[Ian Godfrey]

It sounds like you are getting a decent pedal then it goes away.
I'm assuming you have a suitable tank and lines to feed the master cylinder.
I'd suspect some corrosion occurred either in the rear brake cylinders or more likely the master cylinder while the car was sitting, it really sounds like air is getting in there somewhere or this is a leak.
maybe check again for leaks at every fitting as well.
good luck and let us know what you find.

[Starbucket]

Try adjusting the rear shoes tight to the point that the wheels won't turn, then bleed the front calipers watching the pads after bleeding is complete for them to release as soon as your helper lets up on the brake pedal if they drag your rubber lines have swelled closed inside. Don't forget to loosen the rear shoes before driving. Make sure the MC push rod is adjusted correctly or the front brake port may be blocked.

[gatordub]

All great suggestions. I’ll try those out and report back!

The crazy thing is that if I drive it and use the Motive to bleed it no bubbles come out. This is is after it feels spongy and having to pump the pedal to get the calipers to release.
If I hook up the Motive and pump the pedal I see bubbles.

When I stop or park 9/10 the brakes feel hard. The minute I drive for some distance or turn the wheel I start to lose pressure.

I may just try bleeding the old fashioned way.

[kingkarmann]

[ELFRIED]

put brake fluid in reservoir till full.
open all 4 bleed nipples and let gravity do its work.
might take hours and hours...top up reservoir if neccesary
close all 4 nipples
this is the only way you might be sure there's no air left in the system.

[kingkarmann]

[gatordub]

Thanks all for the great advice!
A couple of observations I'm going to chase down.

1. I jacked up the front of the car and notice that both fronts wheels were a little wobbly. I replaced the bearings and rotors so they be a little loose after test driving. This may have caused some issues with the front brakes push bake against the caliper pistons. I readjusted and tightened the spindle so hopefully that helps some.

2. I tried putting clamps on each brake line to eliminate the a wheel. With 4 clamps I got an extremely strong pedal. With the clamp removed from the rear driver side it got soft again. I'm thinking I may have a small leak in that wheel cylinder so I will investigate more.

[gatordub]

I replaced the rear driver's side wheel cylinder.
The old wheel cylinder was not visibly leaking but when I lifted up one of the boots it hissed and spat out fluid... I'm guessing that's not normal?

I bled the rear brakes with the adjusters fully locked then adjusted the rear brakes and bled all four wheels with the motive power bleeder.

After that the brake pedal was firmest it's felt since replacing the fronts.

Went for a short drive and everything felt great until I got up to around 35 mph. When I braked it felt like nothing was there until I got towards the end of the brake travel.

I can't tell if it's spongy from air or if the brakes are just getting too hot or something else.

I'm also wondering if the stock EMPI pads just stink?

Or related to my previous observation I wonder if there's a problem with my bearings. If they aren't fully seated could they spin when breaking at higher speeds and it feel like I have no brakes?

[Starbucket]

Jack the front up and spin the wheels if they drag the pads are getting hot, take a drive using the brakes once or twice then feel the wheel to see if it's hot or warm, that will be a problem but remember the pads and rear shoes need to seat in. Did you ever check the MC linkage to pedal for some free play? If brake fluid got on your brake shoes replace them or they will "slip".

[gatordub]

I've been busy with family trips and work but finally got a few minutes to mess with the Ghia's brakes today.
I took Starbucket's advise and adjusted the pushrod.
I used John Muir's book for guidance (tighten all the way, then back up half a turn).
Brake pedal is much firmer and now the car is more drivable but braking is still to be desired.
Under 25mph or so the brakes are very responsive and I feel positive brake pedal. When I get up to 30mph+ it sounds like the front pads are dragging and when I brake it doesn't give me a lot of confidence. It almost feels like the front calipers are stuck and it takes a few pumps to get them to release.
Thoughts?

[Starbucket]

Did you replace the rubber hoses to the calipers? The disc's have no return springs so the rubber hoses and lines need to be clear so the fluid returns to the MC. Rubber hoses will look good on the outside but the brake fluid makes them swell closed inside restricting fluid return. Braded SS flex. "Hoses" are Teflon lined and flow freely and give a firm pedal. Remember the pads and shoes need to brake in so braking will improve with use.

[gatordub]

Thanks!
The rubber lines are cheapo brand and less than 2 years old.
It may not hurt to replace them with some quality stainless lines.

[bugmun]

ok i just ran into this issue on a 67 bug in the shop it was on the front on the first master swapped it and then the rears didnt work. 3 masters later wait for it ....... the barbs inserts in the masters are about the thickness of a dime longer than the original so every time you move the resivior line it lifts up just enough to let air in . after trimming it down a litttle best ped evere

[gatordub]

So are you saying the plastic inlets from the brake reservoir move and let air in?
Sorry I don’t fully understand your explanation.

[gatordub]

Quick update.

I have replaced both brake cylinders, checked the rubber lines, adjusted my pushrod length, and re-bled my brakes.

Here is the problem I am still having.

Brakes are hard and feel great pulling out of my driveway and through my neighborhood. I pull out onto the main road and get above 30ish and try to brake. It feels like nothing is there and I have to pump to get a decent pedal. It almost seems like my brakes are semi dragging and pumping resets them.
Could it be that my brakes just need to time to bed?

[Mberglo]

I would replace the master cylinder with an ATK. It's the best $80 you're going to spend. If the system isn't leaking, and you're not low on fluid, it must be the MC. It certainly has nothing to do with bedding the pads/shoes.

[gatordub]

Where did you find an ATK master cylinder for $80?
I just replaced mine with a Brax master cylinder made in Denmark.
It's supposedly 5 stars from CIP...
I'm worried it may be the MC at this point.

[Max Welton]

Having recently read the information posted by Ray Greenwood I would take any new MC or wheel cylinder completely apart for a good cleaning.

https://www.thesamba.com/vw/forum/viewtopic.php?p=9893243&highlight=debris#9893243

and

https://www.thesamba.com/vw/forum/viewtopic.php?t=679160

Max
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