brake issue

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330 4HL
Posts: 22
Joined: Wed Mar 20, 2013 1:01 pm

brake issue

Post by 330 4HL »

The brakes are sticking on intermittently. It is at the master cyl, not callipers. I released pressure to system, then re-bled to allow pedal and hydraulic seal to do full travel inside of cylinder and hopefully free up whatever caused them to suddenly stick. Its working better, but I do not trust it fully yet. I have traced the lines to see if there is an anti-bleed back valve that may be sticking. I cannot see one in line.

Can anyone tell me if these cars have an anti-bleed back valve? There's no mention of one in the manual...
tim
Posts: 341
Joined: Tue Sep 03, 2002 2:48 pm
Location: sacramento, ca

Re: brake issue

Post by tim »

Greetings… Are the brakes applying themselves while you are driving and bringing the car to a stop? I had this problem and it was due to the adjustment of the brake master linkage. Try giving it a little more free play. It might take a little experimentation to get it right.

Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 Turner 950S and some other dull stuff plus a brand Mercedes C300 4matic
cory
Posts: 227
Joined: Thu Apr 14, 2011 7:34 pm

Re: brake issue

Post by cory »

Is the sticking occurring in all the brakes, just fronts, just backs or just one caliper. As Tom would say I would start with the easiest thru a process of elimination. The series 1 does have the pesky equalizer that seems to cause a lot of braking issues. After driving for a period jack the front and rear up and spin wheels to see where or if any brakes are dragging. If its only one wheel then in all likely its the caliper. If fronts or rears are dragging could be the booster for that pairing. Pull the vacuum line off the engine and see if its dry. There should be no oil in it. If there is then you have a sealing issue in the booster. I had an issue with fronts sticking on mine and found it to be the booster with a crushed seal inside. If nothing is found after this testing I would lean to what Tim said.
Cory
Pied-Noir
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Joined: Mon Apr 20, 2009 9:34 pm

Re: brake issue

Post by Pied-Noir »

The series 1 does have the pesky equalizer that seems to cause a lot of braking issues.

Cory[/quote]

I believe you're talking about the 250 GTE. My 330 GT (assembled in June 1964) has a T connector on the front cross member and an identical one on the rear axle. When I redid my brakes, I removed both and cleaned them because I was worried that they were equalizers. They were just plain "T connectors". These connectors identified on TAV 31, numbers 27 and 26 are both labelled as "3 way connectors" P/N 94681. As usual, it's quite possible some very early 330 GTs "may" have been fitted equalizers to use-up some left over stock, but then who knows for sure.
DWR46
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Joined: Tue Sep 22, 2009 8:23 pm

Re: brake issue

Post by DWR46 »

Everybody here is providing good suggestions to help this gentleman sort out his brake problems. However, one item should be addressed. The cylinder found on some cars mounted on the front of the chassis in NOT an "equalizer". It is a HYDRAULIC BOOSTER. it multiplies brake pressure to get more pressure to the front brakes as they do most of the work in stopping the car. It serves the same purpose as the VACUUM BRAKE BOOSTERS. It is found up into the 330 GT production. Yes, they can cause real problems, but I would not recommend bypassing the units. If you remove or bypass this item, you loose brake effectiveness and upset the factory designed brake balance between front and rear.
330 4HL
Posts: 22
Joined: Wed Mar 20, 2013 1:01 pm

Re: brake issue

Post by 330 4HL »

thanks to all for the feedback; I shall attempt to follow each scenario through the system.
More ideas welcome!

BTW, it's just the fronts, but both of them not just one
cory
Posts: 227
Joined: Thu Apr 14, 2011 7:34 pm

Re: brake issue

Post by cory »

Pied
You are correct. The series 1 330 does not have the equalizer. My mis type. As Rick said they only have the front and rear brake T's.
Cory
cory
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Re: brake issue

Post by cory »

Sorry....as Pied said
Cory
tim
Posts: 341
Joined: Tue Sep 03, 2002 2:48 pm
Location: sacramento, ca

Re: brake issue

Post by tim »

Greetings…. My car, an early 4hl SI, doesn't have the booster Dyke mentioned, just the two vacuum boosters. I was having problems about the time Tom went through the trials and tribulations of having one of these hydraulic boosters rebuilt. Check the archives for that story. I spoke with a gentleman who had been in the brake business for a long time. His company was the one that rebuilt the Bendix boosters in my car. He knew right away what the problem was. The piston in the master was still blocking the transfer port causing some pressure to remain in the line and the vacuum booster was multiplying it An adjustment fixed it. This looks like the simplest fix and I would try it first before tearing things apart.

Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 Turner 950S and some other dull stuff plus a brand Mercedes C300 4matic
Pied-Noir
Posts: 38
Joined: Mon Apr 20, 2009 9:34 pm

Re: brake issue

Post by Pied-Noir »

DWR46 wrote:Everybody here is providing good suggestions to help this gentleman sort out his brake problems. However, one item should be addressed. The cylinder found on some cars mounted on the front of the chassis in NOT an "equalizer". It is a HYDRAULIC BOOSTER. it multiplies brake pressure to get more pressure to the front brakes as they do most of the work in stopping the car. It serves the same purpose as the VACUUM BRAKE BOOSTERS. It is found up into the 330 GT production. Yes, they can cause real problems, but I would not recommend bypassing the units. If you remove or bypass this item, you loose brake effectiveness and upset the factory designed brake balance between front and rear.
You're right on this one. Had issues with both boosters not being properly rebuilt. In short the output port cylinders had to be replaced on both. They worked fine until the master cylinder had to be rebuilt. I then had M/C re-sleeved locally with a brass sleeve and that was the beginning of another set of problems. When cold it worked great but when I got stuck in HEAVY traffic (I'm in Southern California), the brakes would hang up and would only release when slapping the pedal hard three to four times and that would release the piston that was hanging up. Don't forget that on the early 330 the M/C sits right next to the exhaust. Well, after taking it apart and checking the bore, I found that the sleeve had been warped when inserted and improperly machined. Then I heated the M/C on a hot plate and found that the 1 inch doughnut seal and piston would hang up on the high spot and would not release. Took it back to get it redone, the owner passed away, the son closed the shop, sold all the scrap metal including my M/C. I was without a M/C for a couple years when I finally found a used one in Spain. In between all that I found a very nice BRAND new and exactly identical M/C which when I took apart had a 7/8 inch rear bore and a 1 inch forward one which was probably from a Lancia. Had I installed it on the car I would have had another bag of headaches. Obviously that was a NO GO. Sent it back.
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tyang
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Re: brake issue

Post by tyang »

Hi Guys,

All these problems are very famiiar to me, and I've had some kind of issue similar to what you're all describing one way or another. Stainless steel sleeves are the way to go, but Brass is easier to machine so a lot of rebuilders use the softer material.

I've also been trying to learn how to rebuild the boosters because of the problems I've been having.

330 4HL, you have a good road map to follow on diagnosing your problem. Let us know what you find, I'll see what I can do to help.

Tom
'63 330 America #5053
Pied-Noir
Posts: 38
Joined: Mon Apr 20, 2009 9:34 pm

Re: brake issue

Post by Pied-Noir »

tyang wrote:Hi Guys,

All these problems are very famiiar to me, and I've had some kind of issue similar to what you're all describing one way or another. Stainless steel sleeves are the way to go, but Brass is easier to machine so a lot of rebuilders use the softer material.

I've also been trying to learn how to rebuild the boosters because of the problems I've been having.

330 4HL, you have a good road map to follow on diagnosing your problem. Let us know what you find, I'll see what I can do to help.

Tom

You should try to get the Hydrovac Bendix manual (if you don't already have a copy). Understanding the workings of the unit and the testing procedures are essential.
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tyang
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Re: brake issue

Post by tyang »

Pied-Noir wrote:
tyang wrote:Hi Guys,

All these problems are very famiiar to me, and I've had some kind of issue similar to what you're all describing one way or another. Stainless steel sleeves are the way to go, but Brass is easier to machine so a lot of rebuilders use the softer material.

I've also been trying to learn how to rebuild the boosters because of the problems I've been having.

330 4HL, you have a good road map to follow on diagnosing your problem. Let us know what you find, I'll see what I can do to help.

Tom

You should try to get the Hydrovac Bendix manual (if you don't already have a copy). Understanding the workings of the unit and the testing procedures are essential.
Yes, I have it, and even purchased a Bendix tester!
'63 330 America #5053
330 4HL
Posts: 22
Joined: Wed Mar 20, 2013 1:01 pm

Re: brake issue

Post by 330 4HL »

Hi all,
I didn't feel the need to rush as you're all in Cali this weekend!
well here's where things stand: It is definitely the master.

Tried to bleed a whole reservoir of new fluid trough to see if it helped, but it did not change.
Removed master cylinder. (Photos attached)

manual lists the following kits for the cylinders: VW Kit #211.698.411
ATE Kit # 3.0470-2425.2
FAG # RK 2527

I went on a search for the VW kits yesterday. Only the dealer was open. We cross referenced the VW# to a 55 to 67 type 2 Bus brake kit. They only had offshore cylinders, but the seals were unremovable.
The four seals require are all exactly the same. There are no numbers or marking on them.

The original master cylinder bore is in decent shape. It can be re-polished if necessary. The main springs and spring washers are not rusty –but maybe the tension has relaxed and the seals have expanded slightly over time, causing the eventual sticking. There was no debris in the correction holes.
I am going to have the local VW shop look into kit source on Monday. Can anyone suggest sources for either master compete, or kit set?
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DWR46
Posts: 621
Joined: Tue Sep 22, 2009 8:23 pm

Re: brake issue

Post by DWR46 »

I have not tried lately, but Ted Rutland , Geoff Ohland and GT Car Parts all used to have those "donut" style seals.
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