Hey guys, long time no post, primarly becuase I have been to dang broke to buy anything for my car. So why did my new master cylinder come with two plastic caps that thread into the holes? Do they have something to do with bleeding? When you bench bleed do you just let fluid drip everywhere? How do you get it from the vice to the car without dripping fluid everywhere, or does it only drip when the little plunger thing is depressed. After bench bleeding is the only way to get air in the master cylinder(not the lines) by running the resivor dry, even if the lines are disconected temporarly. Thanks in advance.

------------------
My 1LE Brothers IROC
SCCA 1LE
89 IROC

She is not the fastest thing in a straight line but she sure will stick in the turns.
Hawaiian Orchid X-SCCA showroom stock 2-time national/ 1 time regional (not with me driving) champ 1LE 92 Z-28 and the family 89 IROC

[This message has been edited by UVA3rdGen (edited November 07, 2001).]

 

Are they plugs or nipples? Plugs for probably keeping moisture out while on the shelf.

Last few MC's i replaced came with plastic barb'ed fittings and a few inches of tubing....put the barb'ed fittings into the holes, tubing on the barbs, and pump/recirculate the fluid until no more air is in the lines coming out.

Place several rags around the area of where you'll be putting the MC...brake fluid eats paint...and pull one fitting, then thread in the hard line, then the next.

There will be some air in the lines, so yu should bleed the brakes.

One thing of note, don't completely top off the MC before you install it, otherwise it'll pour out when you place it. Just leave it about 1/2 full after bench bleeding it.

 

Cool, but one last question, why can't you just do it on the car? Why does it have to been in a vice is basically when you push the brake is does the same thing?

 

You could do it in the car, but you would be spraying fluid everywhere... it would be a PITA that way. They say to do it in a vice just because it will be easier to clean up. Also on the bench you can be sure that you are pushing it all the way in and have a little more control over what you are doing.

------------------
-='89 Iroc-Z - 350 TPI =-


[This message has been edited by BitchinCamaro (edited November 08, 2001).]

 

See, the MC mounts at an angle on the firewall, if you try to bleed it at an angle, you'll never get the air out of it...all the air will rise up.

You put it in a vise to hold it level, so no air pockets occur.

 

You can "bench bleed" it on the car if you jack the rear end up enough to level out the master cylinder.

 

...and that's pretty darn high, too... be safe! When I did that, I took off the front tires, and put the front on low jackstands to save me an extra few inches.

Make sure those fittings (to go to the hoses to lead back to the m/c) fit well enough. The rebuilt m/c I got (from A1 Cardone) had plastic fittings with wrong threads; they didn't seal off right, and air/fluid would ooze out past 'em.

I wound up putting some clear tubing on a junkyard set of m/c-to-prop-valve lines, and leading them back into the m/c.

Oh- also- stroke that piston in/out slowly. (This applies to other things, doesn't it? ) When you let the piston return to "normal", you need to wait at least 15 seconds before pushing the piston in again. This allows the "quick take-up valve" in the m/c body to fill with fluid (and thus, empty of air). You can feel the quick-take-up valve under the m/c... see how the bottom of the m/c body (not reservoir, the body) is flat, until it gets near the firewall, then the bottom bulges out a 1/4 inch? That's the quick take-up valve in there. It's basically a mini-reservoir "inside" the m/c, and it's supplies the m/c with fluid "before" the big reservoir can.

------------------
-Tom P (Hot rodded 1986 Firebird 2.8l)

[This message has been edited by TomP (edited November 09, 2001).]