Itinerant Air-Cooled

also known as "Rebuilding Your Leaky Cheap Master Cylinder Behind A Closed Belks Store".

Yes, I have been empathetically wincing with the poor denizens of the East Coast who have been enduring the Big Storm. Down here in Valdosta, we have been suffering through "breezes" from that very storm. I got slammed with a howling 10 mph puff that picked up the edge of my towel.

So, yeah, all summer my cheap chinese master cylinder has been developing a leak along the trailing edge of the belly pan. Every month, I have had to add brake fluid. Today, I sez, "let's overhaul this sucker." Now, as you know, I cannot afford to screw this up. Brakeless and homeless is a recipe for ending up in a local jail. Went to NAPA.
"I need a 1000 grit sheet of wet-or-dry sandpaper."
"Why do you need wet-or-dry sandpaper? Wet-sandin"?"
"Sort of. I plan to hone my master cylinder."
"I don't think you can do that."
"I don't think so either."

Found a carefully chosen spot behind a big half-dead shopping center with sight lines for brakeless kinetic energy dissipation (should my overhaul FAIL), and I needed a windbreak from the above-mentioned 10 mph howling gale in the 66* sunshine.

Jacked the front end and dropped the brake fluid soaked belly pan:


Because I learn from my prior painful moments of sheer stupidity, I had a whole container of fresh unopened brake fluid!
(see: viewtopic.php?f=44&t=9102 )

Cracked loose the 11mm brake lines and snatched the bleeder boots from the rear wheel cylinders to use as brake line end protection. I used the fuel line clamp to squeeze off the blue supply hose from the upper brake fluid reservoir.
Pulled the supply hose from the priceless reservoir on top of the master cylinder, yanked the brake light switches, and removed the master cylinder. Threw the piece of critically necessary crap inna bucket.
"HEY!"
"Hey what?"
"You can't just park here!"
"Oh, I am not parked. I am disabled."
"What do you mean you are disabled?"
"I mean the car is disabled, I have no brakes."
"You can't just have no brakes."
"I really have no brakes at all, here is the master cylinder."


"Oh geeze. Look, I am the manager of this property, I can't just have you . . . disabled here. I am going to have to call a tow truck in. You're going to have to take it to a shop."
"That will not be necessary. I am going to rebuild it here in one hour flat and be on my way."
"What you have parts or something?"
"Just some sandpaper, 1000 grit, really, it is OK, we'll be OK, I just need an hour, can I get to work now?"
"Are you going to leave a mess?"
"Only if the brakes fail when I get to the stop sign."

He drove off with his smug power-braked Ford F-150. I pondered everything that could go wrong with this stupid master cylinder:
The plastic reservoir on the top could split when I pull it off.
The circlip could sproing into low Earth orbit.
The pistons could score the walls on their way out.
The cups could crack in half as I peel them off the pistons.
I could forget where all the parts go.
But I have a whole fresh container of brake fluid!

Primary disassembly.


Then I peeled the back cup off the piston sooooooooo carefullyyyyyyyyyyyy. Sanded the edges of the cup rubber sooooooooo carefullyyyyyyyyy. This was the maximum point of Yer An Idiot.

Secondary disassembly:
Nothing to lose now. Cleaned all the parts and rinsed out the reservoir with carb spray and a ball bearing for a distributor vacuum advance plate.



Fabrication of brake master cylinder hone:


Honing involved rotating the master cylinder as I pushed the extension/14mm socket/1000gt sandpaper up and down slowly:


Rinsed with brake cleaner, dried off with paper towel. Here is the bore after a good five minutes of slow honing:


Installed the parts back into the master cylinder with a baptism of not very good tasting brake fluid. Here is the completed master cylinder at Minute 52:


And here it is after refitting the master cylinder to the car, loosely until the brake line fittings were threaded successfully, then snugged up. Bled the brake lines from under the car, front circuit first (deepest in the bore). Brake fluid does not taste good.



At Minute 75, the sun shadow enveloped my work space, and those who know will tell you, once I am chilly, I shut down like a lizard:


Fortunately, there was a pedal. No mess at the stop sign, no more leak at the belly pan. The manager was chatting with the security lady on the golf cart as I drove off to McDonalds, McDonalds for coffee on this bone-chilling now 53* evening. Because this quicky little repair actually worked, I can tell you I love these cars for their simple easy elegant design.
Colin

There's the title for this chapter in the soon-to-be-written IAC AdventureBook (tm)

"Slow Honing"

Awesome! exactly what i needed before i launch into the same operation

Lovely!
But I have to ask...why wouldn't a brake cylinder hone and a cordless drill have been easier?

You are my hero!

Hippie wrote:Lovely!
But I have to ask...why wouldn't a brake cylinder hone and a cordless drill have been easier?

If you can find a hone that is 1000 grit as most of the HF ones are too course for a touch up job like this. With 1000 grit you are just polishing the bore to stop a tiny leak.

Hippie wrote:Lovely!
But I have to ask...why wouldn't a brake cylinder hone and a cordless drill have been easier?

I have to answer . . . I had a 3/8" 12" extension/14mm socket brake cylinder hone with removeable grinding media and it was easy enough.

It was sooo cold last night under that icy blue moon, I had to use my sleeping bag for the first time this year. I shall wait until tomorrow's forecast 77* to do the spring plate bushings. Today I will only do projects that allow me stand up and complain about the wind in a windbreaker:
a) fix leak in fresh air damper doors
b) paint touch-up and detail door jambs
c) hunt down twitter in sliding door
d) realign door strikers for a little more Volkswageny feel when the doors shut
e) paint the floor pan at the rust spot under the driver's feet
ColinItIs52*
(do we have mid-northeast forum members here to report on that monster Sandystorm? Cheesehead? Honeybus? Synapse? retro1302? Highlandmurf? )

Bleyseng wrote:

Hippie wrote:Lovely!
But I have to ask...why wouldn't a brake cylinder hone and a cordless drill have been easier?

If you can find a hone that is 1000 grit as most of the HF ones are too course for a touch up job like this. With 1000 grit you are just polishing the bore to stop a tiny leak.

Aha!

What is the best way to get that reservoir off the master without breaking the damn thing?

hambone wrote:What is the best way to get that reservoir off the master without breaking the damn thing?

Hello Hambone.
Did Erin get my ten week late reply to her PM?

Reservoir removal requires only a good grasp of material physics. What we need to do is:
a) apply sufficient force to dislodge the barbs from the rubber grommets
b) distribute that force in such a way as not to exceed the integrity of the plastic
c) by focusing the force as close to the wall of the barb as possible, you can avoid pissing off the chamber floor

I used two fingers under the rear entry point and wiggled the reservoir side to side as I pulled up as close to the grommet as possible. The front insertion point stays in, but watch that you do not "bend" as the rear comes free. Then you repeat for the front.
Colin

Thank you Colin! (I say that a lot...) Can you believe genuine VW reservoir plugs are still available? At least here. And that damn booster for the '73 finally got here so I get to put it all back together, with prayers. I had dreams last night of installing it, weird. I always get a little stressed/anxious, what's new.
Hey, any reason why VW didn't use the blue brake hose to connect the reservoirs? It seems like it would work better than that rigid plasticy hose.

Erin did receive your message, and I did not read it. I'm surprised she didn't respond, she liked it quite a bit.

In a field in Valdosta Georgia next to a little fishing lake, it is sunny and about 75* with no wind today.




Fixed the spooky whistling in the closed air vents by repairing the pushrod bellows with Permatex UltraBlack, no photos, too gummed up to grab the camera. Proudly, yet sadly, I noted that the rubber seals were still perfect, back when Volkswagen wanted to build a good car. Waxed the inside surfaces of the air vent. Chloe, bemused?




Brushed the rust off and sprayed the inside surface of the grill after laying a thick coat of wax on the painted outside surface so the rust-catalyzing primer would not stain the visible paint. Touched up hints of rust at the screw brackets, lubricated the hinges, and applied duct tape to fix the rent screen, yes, rent: past tense of "to rend". Then painted the silvery duct tape so the casual passer-by wouldn't see what a HACK I am.




With such a beautiful day, who wouldn't attack the spare steering box, picked up from Jim at Interstate Parts in Lake Elsinore California waaay back on July 6th?




I must have scored big without knowing it at the time. Neither did Jim, "it is a core, no guarantee, just give me $50.00". It is gorgeous inside, unlike the wretched skipping and clonking of the grey spray-painted "rebuilt" box that is attempting to keep Chloe somewhere in between the edges of the road.

It was very easy to take apart. Try to have a clean garage counter with good lights. Well, I had the good lights, anyway . . . a 268,000 watts per square meter hydrogen furnace lamp.

viewtopic.php?f=45&t=11096

I am trying to rebuild my master cylinder..but am getting laughed at here in Bay Area when i ask for a rebuild kit...am i THAT out of touch with reality..or are they still available?

It is March 29, 2015 at 165,000 miles.
The master cylinder rebuild is still holding up fine.
Colin

Amskeptic wrote:It is March 29, 2015 at 165,000 miles.
The master cylinder rebuild is still holding up fine.
Colin

I love these road side repairs that you have the huevo's to do and document for our enjoyment and entertainment.

Now, edumacate me.. So, there was a small burr or roughness in the bore that the rubber seal couldn't "seal", thus the leak?