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Proper procedure for filling and bleeding completely new aftermarket disc/drum setup
Hi everyone! I have a 72 cutlass supreme with a complete power disc/ drum system from inline tube (MBM) i think. I have not yet filled it with fluid and tried to bleed/ set up the system. Can someone help with the proper procedure for doing this? I dont have the engine running yet so no vaccuum lines yet. Do i need to do this first?
Thanks!
Chris
Should bench bleed master first, I now use a hand operated vacuum bleeder at each wheel. Do not need engine running and works. Start at furthest point, passenger rear and keep master full.
I've been using a pneumatic vacuum bleeder for well over 15 years now. Best tool investment ever. It isn't even necessary to bench bleed the M/C with one of these.
As for whether you start closest or furthest wheel from the M/C, on a dual circuit brake system it really doesn't matter. Just be sure you don't push the piston for the differential pressure switch all the way to one side by pressing hard on the brake pedal with only one half of the system bled. I suggest getting one of these tools to lock the diff pressure switch in place while bleeding.
Thanks guys! Ok. So if I don't have the $100 or so to buy the vacula unit and Im going to do it the old fashioned way, I would bench bleed the mc by using the clear tubing from a bleed kit, hooking one side to the ports, and the other end into the filled mc while it's off the car? Press the plunger in till all the bubbles are gone? Then install it on the lower booster, connect the lines, continue to fill the mc as the level lowers as the fluid drops into the lines? Then open the bleed screws at each wheel into a cup filled with brake fluid while someone pumps the brakes? Or am I going about this all wrong? Should the back of the car be raised?
Thanks guys, this is my first time doing this.
Last edited by Oldssupreme; April 30th, 2017 at 07:53 PM.
To properly bleed brakes with an assistant have them pump the brake pedal gently until a bit of pressure is felt at the pedal. Have them press gently as you open the bleeder at the brake caliper or wheel cylinder. The assistant will push the pedal to the floor gently and hold it until you close the bleeder (if the assistant lets the pedal up before you tighten the valve, air will reenter the system). Then the assistant pumps the brake pedal gently until it gets firm again and holds while you open bleeder valve. The pedal will move to the floor again. Repeat until there is no more bubbles and a steady stream flows out the bleeder. Always check MC reservoir and fill as necessary.
Ok. Thank you! So this is after I bench bleed the mc or not? And I repeat the same procedure for the remaining three after it flows with no bubbles at the first bleeder?
Should bench bleed master first, I now use a hand operated vacuum bleeder at each wheel. Do not need engine running and works. Start at furthest point, passenger rear and keep master full.
This^^
With one of these...
I had to replace every hard line & flex hose on my truck and this tool was worth every bit of the $20.
- No assistant needed
- Find loose fittings/leaks by lack of vacuum prior to bleeding
Ok. Thank you! So this is after I bench bleed the mc or not? And I repeat the same procedure for the remaining three after it flows with no bubbles at the first bleeder?
Yes, after you bench bleed the MC. If you attempt to bleed the MC on the car, because of the angle it hangs you may get an air pocket. Always bleed the brakes in pairs, do right then left fronts or rears.
Or...this one. Amazon $60 maybe even less by now. The one Joe shows is about twice that, and twice as nice. The other one is $30 and not as nice for carpal tunnel victims.
Highly, highly recommend one of these three. You will kiss yourself from then on with a power bleeder. Now you can flush your fluid every 2-3 years like we all should do in about 20 minutes. It will take you longer to jack it up and pull the wheels...unless you have a lift.
I've had bad luck with the Mity-Vac hand pump style bleeders. It seems that every time you pause to pump, air gets sucked back into the bleeder screw - mainly because the bleeder screw threads don't seal in the wheel cylinder. I scored my Vacuula at the Long Beach swap meet years ago for $15.
Eric, when you say to bleed in pairs, do you mean to have both from bleeders open at the same time? Then do both back cylinders at the same time?
Thanks to all of you for your help!
Chris
So, say, bleed right rear until no more bubbles, close valve, move to left rear, bleed until no more bubbles, then move to right front, bleed, and finally repeat with front left?
I had to replace every hard line & flex hose on my truck and this tool was worth every bit of the $20.
- No assistant needed
- Find loose fittings/leaks by lack of vacuum prior to bleeding
F.Y.I...... when having my wife pumping the brakes during bleeding, I use a beer bottle half full of brake fluid with the bleeder hose in the fluid. This helps prevent air from getting into the system.
F.Y.I...... when having my wife pumping the brakes during bleeding, I use a beer bottle half full of brake fluid with the bleeder hose in the fluid. This helps prevent air from getting into the system.
I suggest drinking a beer for each bleeder in case you need more bottles.
If the person working the pedal pushes it all the way to the floor and does not release it until the person tightens the bleeder and tells them to, no air will enter the system. I've been doing it this way for over 40 years, it works.
I like the beer comment but I'm a lightweight when it comes to beer so that would be a self-defeating situation lol.
Eric, correct me if I'm wrong but i thought I saw somewhere not to push the pedal to the floor because of possible damage to the master cylinder piston. Is that true? Thanks!
Lol. Well I live in the middle of the woods so that would have to be one spectacular shot! One more question: in a completely new system with new lines as well, how many bottles of brake fluid would you suggest I have on hand? Thanks so much guys!
Last edited by Oldssupreme; May 2nd, 2017 at 02:30 AM.
I have one of these and used it on my 54 and it worked great. Instead of sucking the fluid and air out of the lines from the master cylinder, it does the opposite. It pushes fluid from the wheel cylinder to the master cylinder and the air in the lines simply bubbles out the master cylinder. It is a one person operation and the thing is cheap. I have not seen anybody else mention it. It worked well for me.
I have one of these and used it on my 54 and it worked great. Instead of sucking the fluid and air out of the lines from the master cylinder, it does the opposite. It pushes fluid from the wheel cylinder to the master cylinder and the air in the lines simply bubbles out the master cylinder. It is a one person operation and the thing is cheap. I have not seen anybody else mention it. It worked well for me.
I've seen those reverse bleeder systems. I'm skeptical. The brake system generates crud in the lines. Normal operation of the brakes pushes that crud to the wheel cylinders, where you suck it out (or push it out) when bleeding the conventional way. Pushing that crud backwards through the combination valve and into the M/C doesn't seem like such a good idea to me.
April 30th, 2017, 06:11 PM
