Service Brakes not retracting (left front)

Discuss fixes, upgrades and modifications to your M37

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rickf
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Re: Service Brakes not retracting (left front)

Post by rickf »

The thing with a vacuum bleeder is to not pull too much vacuum. Just a tiny bit, not even enough to read on the gauge. Otherwise you will suck air in past the piston seals of the wheel cylinders mostly and if you draw too much vacuum you will pull air past the master cylinder cups. If you look at the cups in a wheel cylinder there is nothing at all holding them against the side of the wheel cylinder but the tension in the rubber. They are designed to have pressure against the cup which in turn pushes it out against the cylinder walls. If you draw a vacuum the lips just fold in.
1953 M37
1964 M151A1
1967 M416
1984 M1008
4/1952 M100
12/1952 M100 gone
jim lee
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Re: Service Brakes not retracting (left front)

Post by jim lee »

Well that explains it. As per typical with me.. I was wondering about the wimpy pump in the brake bleeding kit. So I WAY over vacuumed it using the vacuum pump from my old boat company. 29+ in hg.

Not a happy camper that day.

Live and learn. :)

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rickf
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Re: Service Brakes not retracting (left front)

Post by rickf »

HOLY CRAP!!!!!!!!!! I can hear the air whistling past those cups now! :roll: :lol: :lol: :lol: :twisted: Foam was probably an understatement, whipped cream was probably closer. Did it EVER settle out or did you have to pressure bleed it out? And to make things worse you pull in a ton of moisture with that air so unless you completely drained it and started over I strongly suggest that you don't go more than a year before doing a complete fluid change. That can be done without introducing air by simply getting a turkey baster and sucking out all the fluid in the master cylinder and replacing it with fresh fluid. Then open the right rear bleeder and it with the cap off of the master cylinder it should gravity bleed on it's own. Just watch for the amber fluid to go to clear and you know you have the new fluid at the cylinder. Be sure to add to the master as needed. Then close that one and go to the left rear and do the same thing, it will not take anywhere near as long since now you only need to go from the T at the rear axle to the cylinder. Then the right front and left front. After that you will be good for several years.
1953 M37
1964 M151A1
1967 M416
1984 M1008
4/1952 M100
12/1952 M100 gone
just me
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Re: Service Brakes not retracting (left front)

Post by just me »

I don't use a pump! I use an eductor. Best I can pull is about 20" of water, NOT mercury! That is about 1.5"hg. Not much. And I don't run it full blast. This isn't an AC system. I never have a problem with entrained air. The fastest, cleanest and easiest one man method I have found. (other than the automated system I integrated into an assembly line for a motorcycle OEM 20 years ago. Did the brakes and clutch fill and bleed automatically in 15 seconds.)
"It may be ugly, but at least it is slow!"
rickf
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Re: Service Brakes not retracting (left front)

Post by rickf »

You can introduce air with a pressure bleeder also by using too much air pressure. Only use 10-15 lbs. max or you will get foamy fluid there also. There is no easy free ride with this stuff.
1953 M37
1964 M151A1
1967 M416
1984 M1008
4/1952 M100
12/1952 M100 gone
NAM VET
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Re: Service Brakes not retracting (left front)

Post by NAM VET »

Yeah, another problem with a Motive pressure bleeder is failing to replace the tubing occasionally. Several years ago, hooked my Motive up to bleed my Porsche's brakes, and when I just wasn't getting any fluid out of a rear bleeder, went around to check what was the problem, the master being in the front "trunk" compartment. Low and behold, my hose had split, and the Motive pumped a quart of Castrol SRF into the trunk! Since brake fluid is corrosive to paint, I had to take all the carpet and plastic out of the entire trunk, and clean and clean and clean it all out, the best I could. Someday, I should write a book on my automotive mishaps, especially the ones with oil changes starting in the early '60's. Fill a book. My wife hated the car, and made me sell it. Race exhaust, no mufflers, I thought it sounded pretty good. She rode in it once, and said "never again."
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NV
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Re: Service Brakes not retracting (left front)

Post by just me »

And DOT3-4 loves to entrain moisture over air. DOT5 loves to entrain air over moisture.
3-4 is easier to bleed but needs to be changed more frequently to prevent water damage to components.
5 may take several attempts to get a good pedal and get all the air out, but lasts a lot longer. (however, any moisture will pool where it is at)
3-4 eats paint. 5 usually is inert to paint.
My race bikes required fluid changes quarterly.
Anything DOT 3-4 gets fluid changes annually.
I do the DOT 5 annually also as cheap insurance.
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rickf
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Re: Service Brakes not retracting (left front)

Post by rickf »

Loved those Porsches! I used to work for a company that rebuilt them from the ground up. All years going back to the 356 bathtubs. I got to test drive each one before it went back to the customer. Nothing says oversteer like a Porsche under power! :twisted: :twisted: :twisted: They call it drifting nowadays. They push, push, push and then snap loose eventually. Keep you on your toes.
1953 M37
1964 M151A1
1967 M416
1984 M1008
4/1952 M100
12/1952 M100 gone
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Re: Service Brakes not retracting (left front)

Post by jim lee »

My older brother had a 911sc. He loved it, I couldn't drive it. There was no way I could fit in it steer and shift. First gear put the shift knob at about my kneecap. That's kneecap from under my leg.

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Re: Service Brakes not retracting (left front)

Post by NAM VET »

A little story. Several years ago, was driving from SC out to western Nebraska, my wife driving her Mini, me in the GT3, to run in an open road event. I had just had the Porsche's engine out to have the coolant pipes welded in (they can blow out, with catastrophic results on a track), for about $4K at a race ship up near Charlotte. Nearing KC, I finally had a chance to run it up, and had a miss and check engine light. Three flatbeds later, a race shop in KC diagnosed the problem. The first shop had failed to reinsert the second fuel pump's fuse, so the engine ran lean, burning off a piston electrode. Cost was about $7K to fix that. I went back to the original shop and told them I accepted that simple mistakes can be made by anyone, and if they would cover the $2K in parts, I would take the remaining cost. They told me they never make mistakes, and somehow, I must have messed with the fuel pump fuses.

I just turned around, and walked out, and never said a word to them again. My son and I went ahead and ran my wife's Mini in the 52 mile event, and then went back the next year in our GT3 and finally ran it in our Porsche. Chris is a fast driver, here he is at the completion of the run. His daily driver is an Alfa Romeo 4C, the small two passenger sports car.


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rickf
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Re: Service Brakes not retracting (left front)

Post by rickf »

It's fun but it is a young mans sport. I was a semi-pro driver and I was consistently near the top in SCCA and Northeast Modified and Sprint and Outlaw cars. Nowadays I find that in my Mustang GTg I just don't have the reflexes to push it like I used to. I can still play but it is when I already know what the car is going to do so it makes it easier (and safer). Getting old sucks. And yes Jim, I am 6'3" so I know what you mean. I did manage to fit in the many 911's we built though. But I was in my 20's then and quite flexible.
1953 M37
1964 M151A1
1967 M416
1984 M1008
4/1952 M100
12/1952 M100 gone
jim lee
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Re: Service Brakes not retracting (left front)

Post by jim lee »

I'm actually thinking about heating and bending the stick in my Carryall so I have more room for my leg. I figure I could move it to the right by about 6 to 8 inches. Its not like anyone ever sits in the middle seat with all the stuff coming out of the floor.

The M37 is worse. I literally can not drive it wearing boots. Well, I can if I leave the door open. That's how I made it back around the block when I tried doing it.

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Re: Service Brakes not retracting (left front)

Post by NAM VET »

Perhaps the young men who grew up in the depression and later drove these trucks were just smaller in stature. I am 6 two, and like the above chaps, have to raise my brake and clutch leg up to where they touch the back of the steering wheel. I have gotten used to it, but when I come up to stopped traffic, I get ready to apply the pedals before I get near them. The limit in a panic stop isn't my truck's brakes, it is having to pull my feet and legs up to near under my chin to get them on the stop pedals. In the sports car forums I have been on in the past, every one brags how their shifter "falls readily to hand." Well, my truck has the long gear shift lever and when in forth, I can keep my hand on the wheel and put my Pinkie out and touch the gear shift knob. Then of course, the "throws" are about three feet up and down! Not exactly a "short throw gearbox."

But there is something "manly" about moving those big gears in the transmission, like the reduction gears in the Titanic, or the drivetrain in a Locomotive. No panty-waist gears in our trucks. Here...
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Re: Service Brakes not retracting (left front)

Post by Elwood »

NAM VET wrote:Perhaps the young men who grew up in the depression and later drove these trucks were just smaller in stature. I am 6 two, and like the above chaps, have to raise my brake and clutch leg up to where they touch the back of the steering wheel. I have gotten used to it, but when I come up to stopped traffic, I get ready to apply the pedals before I get near them. The limit in a panic stop isn't my truck's brakes, it is having to pull my feet and legs up to near under my chin to get them on the stop pedals. In the sports car forums I have been on in the past, every one brags how their shifter "falls readily to hand." Well, my truck has the long gear shift lever and when in forth, I can keep my hand on the wheel and put my Pinkie out and touch the gear shift knob. Then of course, the "throws" are about three feet up and down! Not exactly a "short throw gearbox."
NV, have you tried the shorter length gear shift lever?
But there is something "manly" about moving those big gears in the transmission, like the reduction gears in the Titanic, or the drivetrain in a Locomotive. No panty-waist gears in our trucks. Here...
Having worked on a full size steam locomotive (all 200+ tons of her...and that was without the tender), the M37 is a pleasantly small and lightweight machine. If you think the jack stands for an M37 are heavy duty, you should have seen the ones we used under the locomotive. :shock:
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Re: Service Brakes not retracting (left front)

Post by NAM VET »

Hi Elwood. Actually, I am quite happy with my long gear shift lever. The prior owner, in Nebraska, replaced the short one with this longer one. Said it made shifting easier when it was 20 degrees below Zero. Me, living in SC, never have to worry much about that. I may ask him if he has the short one in his barn. I took my truck up to Charles Talbert's place two weeks ago, for some maintenance I just didn't want to do my self. Assorted this and that things. i may add a tach to the steering column, next to my Autometer oil pressure gage. I like looking at that hot 55 psi out on the road. Love the spring there, sunny, temps in the mid '60's, going down to Columbia to see my grandsons and help out with some power washing of his son's play set, yard work.

Oh, Rick, when I sold my beloved Superformance Cobra, in which Chris and I tracked thousands of miles, over a hundred drag runs, about four years ago, I too gave up running on a track. Chris got to be pretty good, running with the top Porsche run groups, me, one group down. I was getting slower and slower, i think I just wasn't up to "living on the edge" so to speak. Maybe for all of us, there are life adventures and experiences, that some day become a "been there, done that" sort of thing. Had to admit to my wife last night when she reviewed my credit card statement, that I had indeed bought another rifle, a nice Browning X Bolt in 223. But then I have arranged to work a few ER shifts to pay for my fun, so she was OK with it. But I think she will go shopping this weekend........

Have a great day, guys.

NV
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