Help Cant Bleed Brakes

glemon

Yoda

Offline

• Oct 3, 2009

• #1

I have got the brakes hooked up in my TR250, new hoses, new rear cylinders, rebuilt calipers, some but not all new brake lines. New master cylinder.

I can't get fluid through either end, TR250, dual circuit (front and rear) brakes, with servo. Have tried doing the front first, back first, both. even tried loosening the pipes at the master cylinder and nothing came out, do I have a bad M/C maybe, I may have to drain the fluid out, test the lines etc.

M/C is Lucas made and new, I just took it out of the box and put it one, should I have done something more with it?

 

M

mikespain

Jedi Hopeful

Offline

• Oct 3, 2009

• #2

try pressure bleeding them,or vacuum at the bleed nipple to draw the fluid through,had this problem with a few new master cylinders,or bleed the master cylinder first.Lots of cloth to stop fluid getting on paint work ,loosen pipe off at exit from mastercylinder ,press pedal down,while holding pedal down tighten pipe and then let pedal up ,should draw fluid into master cylinder.BE VERY CAREFUL OF BRAKE FLUID SPILLAGE on paintwork.do same for the other exit pipe and then go on bleeding at wheels.-Have fun-

 

BobbyD

Jedi Knight

Offline

• Oct 3, 2009

• #3

OK....sorry if this is too obvious a question but did you fill BOTH the front and rear reservoirs of the M/C. Sometimes people don't see that little slot for filling the front reservoir which is for the rear brakes. Some guys bench bleed a new M/C but I just did it the old fashioned way and started at the LR and then went RR, LF and RF. It did take a lot of pumping to get it to start flowing.

 

DrEntropy

Great Pumpkin

Platinum

Offline

• Oct 3, 2009

• #4

It really does save time and aggro if you bench bleed an empty master cylinder first. Once on the car it becomes potentially ugly with all that fluid and no way to be certain it doesn't get to the paintwork.

Bobby, is yours a RHD car? Reason I ask is the order you bled the corners.

 

OP

glemon

Yoda

Offline

• Oct 3, 2009

• #5

Yes filled front and back of the MC, I know fluid is getting by the MC because I had a leak at the pressure warning switch thingy, I have already tried loosening the fittings at the MC and giving it a couple pumps no go, unfortunately don't know if I will have much time to work on it today.

 

angelfj1

Yoda

Offline

• Oct 3, 2009

• #6

DrEntropy said:

and no way to be certain it doesn't get to the paintwork.

Click to expand...

doesn't matter if you use DOT 5! :banana:

 

BobbyD

Jedi Knight

Offline

• Oct 3, 2009

• #7

DrEntropy said:

It really does save time and aggro if you bench bleed an empty master cylinder first. Once on the car it becomes potentially ugly with all that fluid and no way to be certain it doesn't get to the paintwork.

Bobby, is yours a RHD car? Reason I ask is the order you bled the corners.

Click to expand...

Nope...LHD..but sometimes my fingers type faster then my brain can process.... and both are slow! RR, LR, RF, LF

 

Geo Hahn

Yoda

Offline

• Oct 3, 2009

• #8

At the risk of sounding pedantic, does it matter whether the car is RHD or LHD? I honestly don't know on a TR250 but on TR2s, 3s & 4s all lines go thru a 3-way or 4-way connector near the RF wheel making the order LR, RR, LF, RF regardless of handedness.

 

OP

glemon

Yoda

Offline

• Oct 3, 2009

• #9

I have a spare cap from the old MC, out of town all this week, but when I get back may try to rig up a pressure bleeder with the old cap, got some ideas from the excellent Buckeye Technical site.

 

T

tomkatb

Senior Member

Offline

• Oct 3, 2009

• #10

Bleeding all of the LBC's, in fact all cars is a PITA.

I assumed I would work on cars for many more years. New cars(our Honda) requires bleeding of brakes every few years in fact. All cars should be bled ever few years.

So i bought a power bleeder. I have a Ezi bleeder(Ebay cast off) and a Motive.

Bleeding your car will take 10 minutes with either. The big job is jacking it up and taking off the wheels.

I cannot believe how easy it makes the job.

I wish I had purchased one of these 37 years ago with my first B. It would have saved many hours.

That said what I used to use a vacuum bleeder to get started and then the beg my wife to help trick. I could never stop some air from getting in the threads on the bleeders under vacuum. My son could sometimes do it with the vacuum bleeder adapters.

My wife thinks the Motive bleeder is the best tool I own.

Larry

 

OP

glemon

Yoda

Offline

• Oct 10, 2009

• #11

I got the MC to pump, the piston got pushed to far in the bore and got stuck, not sure if I did it or it came that way. Now I just have one stupid brake line I made that keeps leaking, I will either have to remake the line or buy a premade I guess.

The good news, modern urethane enamels over epoxy primer seem to be impervious to DOT 3. Yippee!!!

 

DrEntropy

Great Pumpkin

Platinum

Offline

• Oct 11, 2009

• #12

Semi-impervious... don't let it set on there too long!

 

dklawson

Yoda

Offline

• Oct 11, 2009

• #13

As a footnote to the above, if you vacuum bleed the lines (working at the nipples for each wheel), you can wrap the nipple threads with Teflon tape to prevent the bubbles mentioned above. I have a couple of bleed hoses with one-way check valves in them. This prevents me from needing the help of my wife or sons. With a little Teflon tape and one of those bleed hoses I can handle these tasks alone.

If for some reason you are not successful bleeding this MC and you determine there is ANY problem with it, be sure and make a loud noise to your supplier. I recently had a leaking new MC and reported it to my supplier. I was rather disappointed by the lack of concern in their response.

 

G

Guest

Guest

Guest

Offline

• Oct 11, 2009

• #14

Thanks to Frank and DrEntropy for confirming two things: order of bleeding wheels (furthest to closest) and usage of DOT 5 to avoid ruining paint.

Now, for my big question: what is BENCH BLEEDING a new MC, and HOW do you do it?

This is a very educational forum!

Thanks in advance.

 

dklawson

Yoda

Offline

• Oct 11, 2009

• #15

Bench bleeding is where you fill the reservoir of the MC prior to fitting it to the car. A tube is run from each MC discharge port back into the reservoir. Basically you are using the MC as a recirculating pump. You slowly do that until you have only fluid moving through the lines. Then you install the MC in the car, working quickly to remove the return tubes and fit the brake pipes. Even if air does get in, the bore of the MC is usually pretty full so subsequent bleeding goes quickly.
https://www.misterfixit.com/brakbld1.htm

 

DrEntropy

Great Pumpkin

Platinum

Offline

• Oct 11, 2009

• #16

Geo_Hahn said:

At the risk of sounding pedantic, does it matter whether the car is RHD or LHD?

Click to expand...

Pro'lly doesn't matter a whole bunch, but it's always been a bit easier as long as the back gets bubbl'd out first. I do go for the longest line to whichever rear side and work to the nearest front last. I use an EZ-Bleed, too. I love the thing.

RHD has the M/C over that union, but that'd still have me doing the LF before RF in either case.