Where the heck?

[kasen]

Replaced the slave cylinders on both rear breaks, bled all four, still losing pressure and the pedal goes to the floor on the first pump. Thinking it may be the master cylinder. Anyone know where the heck that is located? Still can't find a type 4 411 specific repair manual. By the way, does anyone know where I can find one of those that won't cost as much as the car, itself?
Thanks,
Trish

[Lars S]

The master is down the steering column, under the paper board cover. They are hard to get, someone will come in and advise alternatives.


/Lars S

[kasen]

Thanks Lars! That should be fun to work on. *groan*

[kasen]

Tried readjusting brakes that seemed to help. Probably need new Brake shoes and bleed again. My parts place says they have 3 master cylinders in stock. 2 rebuilt and one oem

[raygreenwood]

Find out who rebuilt them....and use the rebuilt ones. The OEM or NOS (new old stock...meaning they have been on the shelf for eons)...are nearly worthless. the rubber seals harden up over time and will not seal on about 50% of them.

You will most likely find your master cylinder is leaking at the outer shaft seal...and/or has blowby at the seals or the flap valves inside...so it will not hold pressure.

The brake system is a difficult bleed on this car. Put in the new master cylinder. Check and readjust the pedal freeplay if necessary.

ideally...make sure you have shoes and pads that are in spec...not paper thin. Also ideally....at this age...i wouldrebuild your calipers as well. Kits are pretty cheap and these are easy to do.

Adjust your rear brakes well. Then bleed with the emergency brake off. Start at the right rear, then left rear, right front, then left front.

You will need a complete quart of fluid to do this as a bare minimum. This is because the fluid route in the 411/412 has many high points in the system. there are a few in teh front end that when you cannot yet build high pedal pressure...small air bubbles sit in the line and let fluid bypass so you alway have a week pedal. To get perfect pedal you will need to bleed about 3-5 cycles of all four wheels...and then....drive a round abit. i usually drive it for a few days and then bleed again....and you wll ALWAYS get more air and a better pedal. Driving around and using the brakes works these small bypass bubbles out.

Whatever master cylinder you buy...always disassemble it and clean it in alcohol. You would be stunned at the crap that is in these things from the nasty factories they were assembled in. you want to be sure to get any crap out from under the brass flap valves.

What is also very helpful for bleeding is an assistant or a bleeder set up with a spring check valve.

The problem is that when there is a lot of air in the system.....the return stroke of the system is not enough to pull new fluid in. Just not enough suction yet...and not enough pressure yet to really push air....so teh air buubles just move back and forth from the line.

What really helps to get started is the really old fashioned way of having an assistant with a 7mm wrench wait by the back wheel cylinders. you pump about 10 times on the pedal all the way to the floor to expand the cups and build pressure. have assistant crack the valve on the wheel cylindr to release pressure and air. Do not release the pedal until he/she has the valve closed.

Also...bleeder valve screw threads especially on the front calipers...during these early stages of low pressure on the system......have a habit of sucking air back in on the return pedal strok unless the bleeder screw is actually closed while returning the pedal....so if you are using a self bleeder with a check valve...temporaily put teflon tape on the threads. just make sure you remove it when done. Ray

[Piledriver]

I use a mity-vac to get it sucked into the system and flowing well, and the speed bleeders to finish it if I must do it alone.

I don't have a 411/412, but I have some high spots in my setup.

[raygreenwood]

yes...agree on all of that. I have speed bleeders in my front calipers and they are worth every penny. RAy

[kasen]

Thanks Ray and Pile. Next step is to get the brake pads re-lined. We have a buddy at Brake & Equipment that can do it as we have found another part (brake pads) that are almost impossible to replace. Husband adjusted the pads some and the brakes are much less squishy. Drove her to work on Friday and we have an annual gathering titled "Dubs on the Lawn" At a friend's house today. Even in the rain, it's going to be a blast!

[raygreenwood]

Where are you located? Front disc pads and rear drum shoes are readily available for thsi car. they are the same for rear of type 3 and same for front of some type 3 and all 914 (early and late variants). Ray

[kasen]

We're in St. Paul, Minn. Thanks very much for the info. We have a friend that works at Brake and Equipment, where he re-lines brake pads. I think if we clean up the existing shoes, just getting them re-lined will work well. But, it's good to know I have options.

[Piledriver]

If you can have it done by a local, do so.

I went through 6 boxes of rear shoe sets for my late T3 and had to settle for the least quality suck.
(incompletely bonded with gaps under the material etc)

Avoided having to actually install junk on by fitting discs, using 914 rotors, passat calipers.

Worth it if only due to being self adjusting.
It does also stop a bit better/more consistently, partially due to being self adjusting---
---and the self adjusting bits work well as long as you use the handbrake to park.

[kasen]

Ha ha ha! Nice!