Frogman

Ok so I finally got around to installing a new master cylinder, and I'm at the point of bleeding it, the issue is installing this on a 79 is incredibly difficult due to how the stupid brass lines are set up. I noticed both of my Master Cylinders have a bleeder valve on them. My question is, as bench bleeding is almost impossible due to the way id have to insert and rescrew the MC in and I don't want to buy a bleeding kit ( COULD I theoretically bleed them using the little bleeder on the side by pumping the brakes until the liquid stops bubbling?

GSLSEforme

You should bench bleed master cylinder 1st anytime/everytime removing installing it. Not doing this really complicates,raises difficulty of bleeding brake system. Recommend you remove and bench bleed,do you know how to? You can use the caps that plug ports on master/cyl when comes new in box to keep fluid from leaking out while installing.
Only time this is not necessary is if using a vacuum bleeding system such as a Mityvac.

Frogman

I did extensive research last night and found out that bench bleeding is not required for masters that have a dedicated bleeder valve . I simply installed it , topped it off , put a 1/2 cup of brake fluid to a clear tube to the valve and pumped away ( this prevents the master from sucking in air ) once the pressure builds up the air bubbles started comming out , I pumped the brakes ( for a good 20 mins ) until the tube was showing zero bubbles . I closed the valve , topped the chamber off and tested the brakes . They work rock solid now . If any bubbles are stuck I'm doing the drums this weekend and will bleed them there too

GSLSEforme

Good you got m/cyl bled,bench bleeding would have been quicker,easier,then bled brakes,done. Should bleed brakes at all corners of car to flush out old fluid get any air out and run fresh thru, start with RR,LR,RF,LF.

Frogman

Well I'm changing the following parts next weekend .
All the brake lines
Drums + hardware kits.

The disks were replaced two years ago and the calipers seemed fine . Right after I fixed the disks my master cylinder decided to die . I don't know who it was on here but they helped me track the problem down to the master cylinder and helped me track down all the parts I needed ( I greatly appreciate it too ) . Bleeding it was a bitch and I spilled some fluid . Anyways once I get down there I'm going to have to rebleed them but I heard having air in the master causes corrosion and didn't wana risk it .

I also have a second question . My old master cylinder was slotted like a Zero 0 while my new one is a perfect circle . The old one had room for a bracket that holds there the brass pipes combine . I couldn't 're attach it due to there not being enough clearance . But it seems the part doesn't actually need a bracket . If the bracket is structural I can always cut it to fit or simply make a New one that allows the New master to sit flush .

Once again I'm very mechanically illiterate and appreciate all the help you guys give me

GSLSEforme

Air itself doesn't cause corrosion(long term),it's the moisture that gets into the system over time that causes corrosion and is reason why brake fluid should be flushed @every 2 years,30k miles.
Dot 3-4 brake fluid easily ruins painted surfaces in short time. See a lot of older cars that have had a master cylinder(brake/clutch)seeping/leaking long term where fluid leaked out and down firewall,inside and outside that lifted paint over time allowing the affected areas to rust badly. Get down on the floor inside car and observe area where clutch/brake pedals come thru for evidence of fluid leakage.
Pull carpet and insulation away from firewall and look behind for any evidence. If you find evidence of leakage,pull carpet out and clean up area,treat rust and repaint to prevent further damage. Same applies to firewall below clutch/brake master cyls in engine compartment.

While working with brake fluid,bleeding,filling,etc...keep a spray bottle with @20%dish detergent 80% water to spray on areas fluid was spilled,it neutralizes brake fluid and turns it into a harmless liquid that can be rinsed away when done with work in the area. I liberally spray down the painted surfaces in the area i'll be working around/behind/under components being worked on before disassembling components to prevent the unavoidable drips from causing any damage to painted surfaces. When working with brake fluid,use fender covers,blankets to cover fender area. One unseen drop of fluid left in place can ruin the paint it sits on in short order.

Post pic of master cyl/pipes you're talking about. If the associated brake line(s),proportioning valve was bracketed/clamped in place originally,make an effort to reinstall the clamps to anchor the part. Factory did it to prevent the weight of components from fatiguing brake lines from long term vibration leading to cracking of brake lines.

Frogman

I wiped everything I could with a damp towel/soap. I know it ruins paint because of a **** up I did a few years ago.
And yes the bracket was on the proportioning valve, im most likely going to cut part of it off or make a new one using metal plates from the home depot =)