Changing out Master Cylinder any tips

[Roboskid]

The MC on my B1 gave up the ghost. I ordered a new one from Erik's Surplus. Should be here tomorrow according to FEDEX tracking. I have printed out the pages from the TM regarding MC change and the instructions for adjusting the brake pedal travel after the change. I while doing the 2 soldier method of one pressing the brake pedal while the other opens and closes the bleed valve in a container with fluid. It currently has DOT 5 in the system and will remain so. Any tips or suggestions. This is the first time I have changed a MC on any vehicle. I spent about an hour under the truck looking at all the bolts, nuts and lines going to and attaching the MC to the truck. I hope the OD Gods are with me and this goes smoothly.

Thanks in advanced
Sid

[tbone1004]

BENCH BLEED! when you bleed I like to go PR, DR, PF, DF as the order of operations to go farthest to nearest line to the cylinder. Other than that it is pretty straight forward. The pressurized bleed kits are nice to push fluid up into the MC but a bit pricey. Advance auto sometimes has them to borrow

[RMS]

welcome to the board Sid.

be careful with the pipe from the mc to the bulkhead fitting on the frame...... its just a ? mark shape but that little bugger is hard to make. when assembling connect to the bulk head fitting first then the mc, you don't want to cross thread the bulk head fitting. one could end up chasing the line all the way to a wheel cylinder

[ZGjethro]

I bought one of the common pressurized brake bleeder kits, and it has been awesome! It is basically a pump sprayer with rubber stoppers which fit most master cylinder profiles. I made an adaptor for it which threads into the top of the MC cover. Bleeding the M37 is a five minute, one person job. I do my modern vehicles with it and made an adaptor for my KTM bikes' front MC cover. Pressure bleeding is soooo much easier than brake pumping or using vacuum systems, in my experience. If you can't use one of the supplied MC adaptors and need to make an adaptor, you could make your own bleeder with a weed sprayer and a low pressure gauge for maybe $30

[Cal_Gary]

Glad to see this post, ZG, as I'm about to buy one, once I finish my shoe installation.

@Sid, wouldn't hurt to use some penetrating oil on the nuts, fittings, etc. to help free them up.
Gary

[pwrwagonfire]

It's a nice and easy job...pretty straight forward!

I made sure to bleed the living hell out of mine when I was finished

-T

[Cal_Gary]

Just had to weigh in since I did my power bleeding today-the power bleeder might just be the BEST money I've spent on my M37! I always had marginal brakes at best, but doing the full brake overhaul (turned drums, new wheel cylinders, master cylinder, brake lines, and oversized shoes) has left me with full braking capacity (save 1 weeping wheel cylinder that I'll fix this week). I still have to do the final adjustments, but will second ZGs comment-power bleeding is the only way to go!
Thanks,
Gary