65 vert brakes went out

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bengill
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65 vert brakes went out

Unread post by bengill » Tue Jun 13, 2017 6:22 pm

Hey guys, I was driving home here in the bay area and luckily in traffic when I went to press the brake pedal and went all the way to the floor. Now I do have the dual master cylinder so I was able to stop the car cause I was only going about 5 miles an hour and I use the parking brake to get myself to a safe location. I don't see any fluid leaking from any wheels wheels and I pull the top off of the master cylinder and it looked for. And waiting on a tow truck now but when I get home what are some things I should check I'm assuming that it's probably a wheel cylinder that has popped a piston seal


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skipvair
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Re: 65 vert brakes went out

Unread post by skipvair » Tue Jun 13, 2017 6:37 pm

Popped a brake
Line once.


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toytron
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Re: 65 vert brakes went out

Unread post by toytron » Wed Jun 14, 2017 3:35 am

If the MC looks full then you might have a leak between the two reservoirs in the master cylinder. Also check your carpet behind your brake pedal it might have brake fluid on it.

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66vairguy
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Re: 65 vert brakes went out

Unread post by 66vairguy » Wed Jun 14, 2017 9:49 am

You didn't say what your brake configuration is.

A dual master cylinder with an internal, or external, failure will typically go ALMOST to the floor, but there will still be some braking action, albeit reduced. That' s normal and it's happened to me a few times in high mileage cars.

If you had NO braking action then it could be a complete MC failure (unusual) or the MC is not correctly matched to the brake system. I've seen front disc brake conversions that worked fine until you opened one circuit and the pedal bottomed out due to a lack of cylinder volume. That's why disc brake cars got bigger MC piston diameters that REQUIRED a vacuum booster to deal with the resulting higher pedal pressure (bigger the MC cylinder vs. wheel cylinders the higher the pedal pressure).

bengill
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Re: 65 vert brakes went out

Unread post by bengill » Wed Jun 14, 2017 8:16 pm

I did have a little bit of braking action all the way at the bottom of the brake pedal travel. I just took the wheels off and the drums and they are dry so I think I'm going to change out the master cylinder I don't know what kind of car I came off of though because it was on the car when I bought it. Any ideas?Image


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bbodie52
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Re: 65 vert brakes went out

Unread post by bbodie52 » Wed Jun 14, 2017 8:31 pm

Image

:link: http://www.corvair.com/user-cgi/catalog ... N&page=145
Image

Part number C1196R: MASTER CYLINDER-67-69-NON GM-ALSO ORDER ALSO ORDER GSKT=C1199P (C1198 BOOT INCLUDED)

Weight: 7 lbs 0 oz
Catalog Pages(s): 145
Price: $ 90.45



Image
:link: http://californiacorvairparts.com/index ... er=product

Image

DUAL MASTER CYLINDER 1967-69

Part No. CC07056R


$60.00
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible

bengill
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Re: 65 vert brakes went out

Unread post by bengill » Wed Jun 14, 2017 8:43 pm

Thanks


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Spike65
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Re: 65 vert brakes went out

Unread post by Spike65 » Thu Jun 15, 2017 2:26 pm

Both Clarke's and California Corvair indicate it is for '67-'69 model. Is it appropriate for a '65?

Thanks in advance.

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bbodie52
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Re: 65 vert brakes went out

Unread post by bbodie52 » Thu Jun 15, 2017 3:00 pm

It is a stock replacement for a 1967-69 dual master cylinder, which was stock in those model years.The 1962-66 upgrade kit, which upgraded the earlier Corvairs from a single to a dual master cylinder utilized this same dual master cylinder as a part of that upgrade kit (along with some new plumbing). The upgrade master cylinder was not compatible with the early mounting configuration on the 1960-61 passenger car.

Rebuilding the old dual master cylinder using Clark's rebuild kits may be an option, if the old master cylinder is confirmed to be faulty, if it is of a type that is compatible with the rebuild kits, and if the old cylinder bore is not rusted, corroded or pitted in a way that would make it a poor candidate for rebuilding. Rebuilding the old master cylinder could save money.
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66vairguy
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Re: 65 vert brakes went out

Unread post by 66vairguy » Thu Jun 15, 2017 5:01 pm

Spike65 wrote:
Thu Jun 15, 2017 2:26 pm
Both Clarke's and California Corvair indicate it is for '67-'69 model. Is it appropriate for a '65?

Thanks in advance.
The single MC cylinder bore for the single 65-66 and the dual MC 67-69 are the same, so it works fine in a 65.

Your MC plumbing looks typical for a modified to dual MC 65-66 car, BUT make sure the front MC line goes to the rear brakes and the rear MC line goes to the front brakes.

The 67-69 Corvair had a lot of plumbing and a "T" block that folks confuse with a proportioning valve that it is NOT. The "T" with the wire was a simple switch to illuminate a BRAKE warning lamp on th 67-69 cars if either circuit lost pressure.

The 67-69 dual MC for manual brakes was used on a number of GM cars of the era and is available new at any auto parts store. I wouldn't waste my time and money on a rebuild kit as your MC cylinder bore has to be in good shape and typically is NOT and you would need a honing tool.

O'Reilleys new dual MC is about $30.00, Rebuilt is about $21.00.

If you haven' t "bench bleed" a dual MC they get the kit at the autoparts store. DON'T bottom out the piston while purging air.

bengill
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Re: 65 vert brakes went out

Unread post by bengill » Fri Jun 16, 2017 10:05 pm

I got the master cylinder today from O'Reillys. I'm not in a rush to get the car back on the road so once it cools down here I will Bench bleed the master cylinder. I've done it before but I don't happen to have a vice this time to Clamp it in so I'm guessing it will just take me longer to do it by hand.


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bengill
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65 vert brakes went out

Unread post by bengill » Sun Jun 18, 2017 7:09 pm

So the master cylinder I got from the FLAPS was a little bit different it bolted up just fine but the reservoir Instead of being the snap on type had a single bolt in the middle.......I didn't think anything of it but I bled the brakes today and did two rear drums bled just fine but I got nothing coming out of the front drums... as I understand the dual master circuit to work is that one circuit controls left rear and right front and the other one controls right front and left rear. Am I mistaken on that? Or did I just get the wrong master cylinder. I got one from a 68 is what I have


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66vairguy
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Re: 65 vert brakes went out

Unread post by 66vairguy » Sun Jun 18, 2017 8:38 pm

bengill wrote:
Sun Jun 18, 2017 7:09 pm
So the master cylinder I got from the FLAPS was a little bit different it bolted up just fine but the reservoir Instead of being the snap on type had a single bolt in the middle.......I didn't think anything of it but I bled the brakes today and did two rear drums bled just fine but I got nothing coming out of the front drums... as I understand the dual master circuit to work is that one circuit controls left rear and right front and the other one controls right front and left rear. Am I mistaken on that? Or did I just get the wrong master cylinder. I got one from a 68 is what I have


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Your thinking of the old European dual circuit system. The GM dual MC is to the front on one circuit and to the rear on the other. The problem you are describing may be a dual MC with air in the MC or lines. A dual MC is a PITA to bleed and why I mentioned the kit that runs lines from the outlets to the reservoir so air does not get back in when releasing the plunger during bleeding. DO CHECK TO SEE IF THE MC FRONT FITTING GOES TO THE REAR BRAKES AND VICE VERSA. It's counter intuitive and folks sometimes mix up the lines. If you still can't get fluid out the front (I assume you are pumping the brake pedal) you may have to use a pressure bleeder (pressure at the MC or vacuum at the wheel cylinder). I gave up decades ago trying to bleed dual MC units with the pedal and use a power bleeder.

bengill
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Re: 65 vert brakes went out

Unread post by bengill » Mon Jun 19, 2017 5:58 am

66vairguy wrote:
bengill wrote:
Sun Jun 18, 2017 7:09 pm
So the master cylinder I got from the FLAPS was a little bit different it bolted up just fine but the reservoir Instead of being the snap on type had a single bolt in the middle.......I didn't think anything of it but I bled the brakes today and did two rear drums bled just fine but I got nothing coming out of the front drums... as I understand the dual master circuit to work is that one circuit controls left rear and right front and the other one controls right front and left rear. Am I mistaken on that? Or did I just get the wrong master cylinder. I got one from a 68 is what I have


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Your thinking of the old European dual circuit system. The GM dual MC is to the front on one circuit and to the rear on the other. The problem you are describing may be a dual MC with air in the MC or lines. A dual MC is a PITA to bleed and why I mentioned the kit that runs lines from the outlets to the reservoir so air does not get back in when releasing the plunger during bleeding. DO CHECK TO SEE IF THE MC FRONT FITTING GOES TO THE REAR BRAKES AND VICE VERSA. It's counter intuitive and folks sometimes mix up the lines. If you still can't get fluid out the front (I assume you are pumping the brake pedal) you may have to use a pressure bleeder (pressure at the MC or vacuum at the wheel cylinder). I gave up decades ago trying to bleed dual MC units with the pedal and use a power bleeder.
I did use a bleeder kit when I bench bled the MC. I will double check the lines to make sure they are going where they need to go. I did notice that I have my assistant was pumping the pedal I could still spin the front drums. I don't have a power bleeder were air compressor so looks like I'm going to have to move it down to the local repair shop and have them finish it up maybe


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bengill
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Re: 65 vert brakes went out

Unread post by bengill » Wed Jun 28, 2017 8:48 am

So I just got word from the local repair shop here that when they put the power bleeder on it it started to puke break fluid from the front lines that go from the drums to the firewall. I'm assuming that these two lines connected to junction block underneath the brake pedal? When I talk to him and he started to talk about everything he needed to be removed it sounded like he was just gonna start to rack up the labor charges. So I'm waiting to hear back from him he says that the control arm and the sway bar and the fuel tank all need to be removed in order to access those lines. So my question to you guys is, is the accurate about all of that being removed if he is I'll let him do the work because it's not something I can do in my driveway but I just want to make sure I'm not being taken for a ride. I'm going to call a couple other shops and get estimates based off what he told me


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bbodie52
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Re: 65 vert brakes went out

Unread post by bbodie52 » Wed Jun 28, 2017 10:25 am

:think: :whoa: :sad5: A ruptured brake line — if it is a steel tubing brake line — could be an indicator of a larger problem. Brake fluid is hygroscopic and absorbs moisture from the air over time. Excess water build-up in the fluid can rust steel brake lines and cause corrosive damage to the internal wheel and master cylinders. Moisture in the brake fluid will also lower the boiling point, which can result in early brake fade as the brakes get hot. So if you're aging Corvair ruptured a steel brake line at some point in the system while it was being subjected to pressure bleeding, internal rust and corrosion could be a problem throughout the car. If the brake line that ruptured is brake line "B" in the diagram below, it would be necessary to remove the stabilizer bar and the fuel tank to gain access to replace that particular line. As noted in the page from Clark's Corvair Parts below, replacement of some lines requires removal of the fuel tank or rear suspension components. Other lines can be routed and installed without having to remove significant components within the car to expose the line.

If moisture in the brake fluid has caused decay and deterioration of your solid brake lines, interior rust or corrosion could also be accumulating within the master cylinder and wheel cylinders. The flexible brake hoses at each wheel are also subject to swelling and deterioration over time.

Obviously you will need to replace a ruptured brake line. The line routed between the master cylinder plumbing in the right front brake is difficult because of the need to remove the fuel tank to gain full access. Replacing the ruptured line will get you back on the road, but you still need to be concerned about the condition of the remaining lines in the system. Other lines may rupture in the future, and it is impossible to predict the condition of each line internally, or how long they may last. As you discovered already, even a dual master cylinder only gives you some limited breaking when a rupture occurs. Of course a Corvair that is fitted with a single master cylinder would have no breaking at all with such a failure. Either way, there is no advance warning when a brake line is going to give out, and loss of breaking could result in a collision and serious damage to the car and possible injury to the passengers. You may want to consider this as you decide your next steps in repairing your car.

I had a steel brake line rupture in my late-model GMC pickup truck, and that occurred in my driveway when I stepped on the brake pedal to shift the transmission into DRIVE. In my case, the line that ruptured was in the engine compartment, near the power steering pump. Examination of the brake lines throughout the truck showed significant corrosion on most of the lines. With antilock brakes the plumbing was quite complex and expensive to replace. Your Corvair is simpler, but replacing all of the lines throughout the car would be time-consuming. Even if you do all of the labor yourself, the cost is not insignificant. The use of stainless steel brake lines for your replacements is a possibility, but it adds to the cost. Completely flushing your system and replacing any corroded wheel cylinders or master cylinder might also be needed, and this might be a time to consider an upgrade to silicone brake fluid, which is not hygroscopic. (Switching brake fluid types requires completely flushing and eliminating the old brake fluid, before filling the system with silicone brake fluid). Otherwise you should be planning on flushing and changing the brake fluid every few years in your Corvair.

Fuel Tank Removal & Installation
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1965 Corvair Front Brake Lines (Caveat)
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1965 Corvair - Front Brake Lines
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:link: http://www.corvair.com/user-cgi/catalog ... w_page=144
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Attachments
1965 Corvair Assembly Manual - BRAKES.pdf
1965 Corvair Assembly Manual - BRAKES
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Brad Bodie
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