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Had a slight weep from my brake master cylinder, brake fluid dribbling down the brake pedal so ordered a seal kit and removed the master cylinder, stripped it down. Bore is fine and rebuilt using new seals. I have since bled the entire system using Gunson easybleed kit with several litres of dot 4 through it. I'm not getting a decent pedal at all despite this. Do I need to do a manual bleed by pumping the brake pedal as well with an assistant since the master cylinder was emptied?
I actually took it off again today and stripped it again to check I had the correct sized seal kit fitted. Being a '63 it would have originally had a 0.75" bore master cylinder but it has obviously had a later 0.7" fitted over the years.

Any ideas welcomed.

I say forget the ezebleed and start again, using the old, well tried press - hold - release method as taught by zillions of dads to their sons who taught their sons who used their mates (or wife's) to help since we first had hydraulic brakes. My wife is a past master at it - and brake bleeding too!.

My son knew that as well as doing the press-=hold and release job, his other job was to keep the cylinder topped up. And he was in for an arse kicking if we had to start again especiially as I use silicon.

Start at the furthest away and work your way towards the closest seems to be the book way although I just start and end anywhere to be honest

If you lived near Oxford, we'd have that done and dusted and drinking a cup of tea within an hour.

You did get the seals in the right way up..?

I find the Ezibleed good for starting a dry system, but once you have fluid flowing, the old skool method of pedal pumping, tube on the nipple to a jar, the best way to get all the air out.

I always bleed the master cylinder on the bench then fit it to the car, I’ve never used a pressure bleed system on anything.
D

gs.davies wrote: ↑Sat May 11, 2024 9:32 pm You did get the seals in the right way up..?

Yep. I did question myself and checked.

Guess one of my sons is getting a mechanical education tomorrow!

Another ploy I use to get the fluid moving around the system is keep the nipple (you're working on) closed and tell the press-hold-release (the PHR) slave to press down really hard, This compresses the air in the system. Then open your bleed nipple. This way you get the load from the PHR mans foot PLUS the additional load of the compressed air reasserting itself. Works for me.

That’s what I usually do as well, and I change the nipples if I have any doubts about them too.

You're dead right too Norman. And make sure that you fit those little ribber caps over them too. Especially if you're still using that moisture absorbent fluid.

The little rubber caps are readily available on ebay. I looked them up under 'nipple covers'. You won't believe the variety things I was offered......!

I know people will say it's a bit picky but I have used those little dental brushes called INTERDENTAL brushes (from the healthcare section at Tescos) to scrub out the wheel cylinder bleed nipple housing and threads.

Its not a bad idea to bleed the master cylinder first, before you connect the brake line to the rest of the vehicle. I think the Eezibleed instructions actually say to do that on a Mini. I have no idea why it helps, but I had a lot of trouble with my Traveller until I did that. I made up a hose on a scrap piece of brake line that screws into the top of the M/C to guide the fluid into the waste bottle. Bleed the M/C, then connect the rest of the system and bleed the lot.

I use an Eezibleed because no-one in my household will pump the pedal for me. It works well but does tend to use a lot of fluid. Its important to reduce the tyre pressure or it blows the cap off, and might actuate the pressure compensator on the rear subframe.

Tim

I use Eezibleed to fill the system. Then I leave the Eezibleed in place (to keep the master topped-up continuously) while I get someone to pump vigorously as I do the open/close thing on the nipples in sync. This always gets more air out - often quite large bubbles. Afterwards the pedal is a lot firmer than just using the Eezibleed. I suspect this air comes especially from the rear limiter and the wheel cylinders, because I don't think the exits of these are necessarily at the very tops of the devices. So a good speed of flow is required to drag the air out.

Interested in how to bleed the master cylinder on the bench. I am imagining holding the master cylinder vertical and pushing the pushrod down on the bench - is this correct? How does this improve from using a foot with the pedal connected?

floormanager wrote: ↑Mon May 13, 2024 6:47 pm Interested in how to bleed the master cylinder on the bench. I am imagining holding the master cylinder vertical and pushing the pushrod down on the bench - is this correct? How does this improve from using a foot with the pedal connected?

Yes that’s correct
I put a bleed nipple in the top and use the bleed bottle, it was just the way I was tough many years ago.

"If you lived near Oxford, we'd have that done and dusted and drinking a cup of tea within an hour."
Hang on Peter. I'm feeling thirsty and in need of a bleed. When can I pop over?
Cliff

Is there a need to check the servo for air?

That made me chuckle Cliff........ Regards

Cammsjb wrote: ↑Mon May 13, 2024 8:52 pm Is there a need to check the servo for air?

No servo on this car.
Got my son to do the pedal tonight, it's better but still not fantastic

"Servo so for air" (So far So far) Wained on 1960s 4 wheel drum braked Minis. Always carried a diary and learned to "Anticipate" hazards well in advance.