Brake Master Cylinder Anatomy - mklotz70

[mklotz70]

I put up a new page on my site. First part is taking apart a m/c.....couple other vids of the cut-away mod I did to it :)

 

http://www.bluehandsinc.com/brake-master-cylinder-anatomy.html

[hawaii_620]

Nice videos!

[mklotz70]

Glad you like them :) It's giving me a reason to learn how to use my vid editing software. hhmmm.....maybe that m/c will be part of next years Ratsun award?? It's hanging on the peg board at the moment :)

[Nicholas7620]

Very cool, Mike, outstanding work. Makes me want to get a video camera and editing software. :P

[mklotz70]

Thanks :)

I use a $140 camera and a program that cost me about $40...maybe 60. I enjoy doing them. If I could get away from working on cars, I'd do more of them :)

[elmerfudpucker]

I have to wait to see them, I cant get them thru the firewall at work. :(

[wayno]

Nice Mike, good job, must have been nice to have it come apart so easy, it never goes that smoothly for me.:lol: On a side note, when I was changing over to the dual system, I also pulled apart one of the master brake cylinders to try to figure out why it wouldn't work, turned out that the keeper holding the reverse circut in and centered that you removed with the screw driver was on the wrong side of the piston circut, when I pushed the plunger all the way in, the reverse circut plunger stayed on the bottom of the cylinder hole, it would never have worked anyway, because the keeper was resting on the plunger seal, and if it wasn't ruined already, it would not have lasted long. The keeper is supposed to be in the middle of the plunger circut, not on the end holding it down, it was assembled wrong when rebuilt.

[mklotz70]

Thanks Wayne.

 

Ya....if you watch closely in the last vid as the m/c is turned around, you can just make out that the pin is in the recess of the back piston....holding it from going forward.

[Figbuck]

M, I just replaced my 620 master again because the backs were spongy... If you remember I thought the back brakes were shot, and indeed one drum was scored... so I just thought the funny pedal feel was that. Now I have all new rear drum parts and the rear circuit is fucked in the master. Two maybe three oil changes on a reman and it was toast. My memory is that the stock OEM master was in there for 30 years and a couple hundred thousand miles.

 

I just tried to get a new one and unless somebody else tells me different. It seems like they are N/A.

 

I think I told you the story about when I had the truck all apart in the garage for almost two years. When I finally got it all together, I fired it up and started to back out of the garage. I put it into reverse and slowly let the clutch out, give it some gas... then I pushed on the brake and it goes to the floor!! I push the clutch and nothing happens!!! the truck slowly backs out of the garage and I can't take it out of gear or stop! I hadn't put the mirrors on it yet either... I end up hitting the side of the house with the back corner of the bed... that I just spent months straightening and painting!!!!

 

So here is my question: Can you get a rebuild kit for these masters?

 

I told somebody that story and they said you can get the plunger parts to rebuild them at a place in Gresham. The guy gave me the card and then said, you know those things are only like $40? It ain't worth even touching them. I'm looking for the card. I know I have it... just moved too many times now.

 

Well if they are only going to last ten thousand miles or something, I'd almost rather sit down and rebuild a couple of them so I have spares. What are your thoughts?

[mklotz70]

Fig....sorry for the delay! This notification scrolled up, off my screen because of other emails....I just came across it. I try to keep up on the notifications, but it's always safer to pm or email me if you're trying to get in touch with me.

 

I haven't heard of any place in Gresham. OTT's friction supply would be where I would start looking for a rebuild. Have you checked RockAuto?

 

What fluid are you using? ...hhmm...I know we used my fluid in the fronts, but I don't think we did anything to the rears.

 

If you pull the e-brake on...then pump the brake pedal twice and press firmly....is it squishy? Setting the e-brake will engage the shoes, then the 2 pumps will fill the wheel cylinder and have the hydraulics engaged. At that point, the pedal should feel pretty darn solid. If you press firmly and it slowly goes down, there's a leak in the system some where. If it feels spongy, then something is flexing, bending, or there's air in the line. What's the status on getting the rear discs on? I thought that was going to happen a couple of weeks ago. Too bad I didn't save a couple of the drums I cut the centers out of....they would make a cool troubleshooting tool! They would hold the shoes in and you could still see the brakes activating. My plasma cutter is working again.....I guess I could make a couple. :)

[Figbuck]

It was more of a general question. Yeah Friction Supply. Might find a packing kit for clutch master too. If it was only a couple bucks it might be worth doing a couple for spares. No, I just wondered if you might know off hand about the place this guy mentioned.

 

I'm pretty sure the master was knackered before you even touched it. As it stands now, I have a new reman master, the front discs are 'sweet', the rear got new drums, wheel cylinders and shoes (thanx Jason your a prince). The truck is like a new vehicle... I'm having to learn how to drive all over again. Just a toe on the pedal slows it on the freeway and and coasting up to stop signs. If you need to stop right now, it goes down, but hits a good solid spot that you can stomp on. I haven't had the chance to break it loose at speed yet. I'm looking forward to hustling it through the corners on some of my favorite back roads too.

 

The main reason I want rear discs is for towing my motorcycle trailer... but I don't have any bikes right now... and I have other Datsun projects that need attention. It will get done... it just got moved down the list. My truck is going to be 39 years old in week or so. It's enough just to keep pulling maintenance on it when it's a daily driver. To make major changes like working brakes is life changing. Driving for the last year I assumed that I didn't have brakes... because I never knew when they would engage or not, then grab and pull the wheel out of my hand. Then I was never sure which way it was going to grab either... soo hairball at any speed.

 

I got an idea Mike. You could come up with the matching hot set up solution for the 620 rear disc and I can be your test subject. You make 'em and I'll try to break 'em. :lol:

 

Brake kit upgrades by Blue Hand Performance Products/Midnight Productions. Thanks again for your help man.

[mklotz70]

I'll bet that "solid spot" in the brakes is when the rear shoes become fully engaged. Once they get broke in a bit, I'd readjust them to where they just scuff lightly.

 

I like the name :)

 

You're more than welcome Fig :)