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Bleeding minis!

Posted: Wed Dec 18, 2024 9:44 am
by Jasonking
Hi, fitted new slave cylinder and pipe, now as usual can’t bleed the flipping thing! Do those vacuum pump things actually work? Any thoughts or tips? Ta :D

Re: Bleeding minis!

Posted: Wed Dec 18, 2024 10:03 am
by Peter Laidler
Not enough info Jason...... What happens when you press the clutch pedal? Does the lever move at all?

As for the vacuum thinggy, don't know. Never felt the need to try one as the usual way has never failed me!

The clutch bleed system is as simple and direct as it gets with hydraulic systems

Re: Bleeding minis!

Posted: Wed Dec 18, 2024 10:55 am
by gs.davies
There's only two moving pieces in the system, the master cylinder piston and the slave cylinder piston. If there's nothing coming out of the new slave cylinder along the new connecting pipe, then the seals in the master cylinder are so shot that they're not pushing the fluid along, or there's a blockage in the metal pipe or inside the master.

Re: Bleeding minis!

Posted: Wed Dec 18, 2024 10:59 am
by mab01uk
Jasonking wrote: Wed Dec 18, 2024 9:44 am Hi, fitted new slave cylinder and pipe, now as usual can’t bleed the flipping thing! Do those vacuum pump things actually work? Any thoughts or tips? Ta :D
A 'Gunson Eezibleed' is worth every penny in my opinion for brakes or clutch.
Halfords have them for only £22.99:-
https://www.halfords.com/tools/hand-too ... lsrc=aw.ds

Or £62.45 from Gunsons direct but may be a better kit?
https://www.gunson.co.uk/product/G4062/Eezibleed-Kit

Gunson Eezibleed
"This system sets the standard for affordable brake and clutch bleeding systems. By using the air pressure from the spare wheel, the Gunson Eezibleed will effortlessly bleed any hydraulic system. There are several adaptors available to fit most vehicles with screw cap reservoirs, and comprehensive instructions are included.
Bleeding the brakes by pumping the brake pedal frequently has one big drawback: the piston inside the master cylinder can travel past the slight lip on the bore that has formed with normal usage, possibly damaging the seal. This does not happen with a pressure system such as the Gunson Eezibleed as the master cylinder piston will not be moving. If new components have been fitted, or the fluid is contaminated, the system must be bled.
The one-man brake bleeding system — connects to your car’s reservoir with one of the selections of caps provided in this kit. The new brake fluid is pressurised by attaching the Eezibleed tube to the spare tyre. Then release the brake bleed valves in turn and let the air bubbles and old fluid flush out through the drain tube. Pressure bleeding of brake and clutch hydraulic systems is recommended by most manufacturers."

Re: Bleeding minis!

Posted: Wed Dec 18, 2024 11:14 am
by floormanager
Ditto for Ezi-bleed. Fitted a re-rubbered clutch master, could not prime it. Ezi-bleed sorted it. I read on here, it's best to pre-prime them on the bench before fitting them. I know do that.

Re: Bleeding minis!

Posted: Wed Dec 18, 2024 11:20 am
by MiNiKiN
I use a mahussive syringe - the vacuum of this usally sucks out any air better than those commercially available bleeders. Even managed to bleed the beeping rear brake pipe of my MGF (which runs ca. 30cm upwards and then downwards agian to the calipers - perfekt air trap :evil: )

Re: Bleeding minis!

Posted: Wed Dec 18, 2024 4:57 pm
by Peter Laidler
Not quite on this particular subject, but bleeding generally, I was always taught to leave the nipple closed and press down hard on the pedal. In the case of the clutch, then you'll have to prevent the lever from moving outwards of course.

That way you really compress any air in the system to the Nth degree. Tell helper to open the nipple and the compressed air does the rest as it blasts its way to the now open nipple. Close nipple and repeat....

I trust that you have a modified bleeder fitted to your slave cylinder?

Re: Bleeding minis!

Posted: Thu Dec 19, 2024 2:19 am
by Jasonking
Modded bleeder? Dunno, it’s a brand new oe Lockheed jobby from Minispares.

Re: Bleeding minis!

Posted: Thu Dec 19, 2024 6:50 am
by Exminiman
floormanager wrote: Wed Dec 18, 2024 11:14 am Ditto for Ezi-bleed. Fitted a re-rubbered clutch master, could not prime it. Ezi-bleed sorted it. I read on here, it's best to pre-prime them on the bench before fitting them. I know do that.
Ditto, now less than £20. https://www.amazon.co.uk/GUNSON-G4062F- ... a4018d2e41

Re: Bleeding minis!

Posted: Thu Dec 19, 2024 6:54 am
by timmy201
I find the usual clear tube bleeder is the best for a mini clutch. You use a long length that will go all the way up to the master. It should be able to bleed 99% of the air out without any pumping required

You can use the little bleeding bottle or just go back into the master
IMG_2928.jpeg

You can install a remote bleeder like this that Peter is suggesting but it’s not essential, especially on basic minis with no servo or heater
IMG_2929.png

Re: Bleeding minis!

Posted: Thu Dec 19, 2024 11:13 am
by floormanager
timmy201 wrote: Thu Dec 19, 2024 6:54 am
You can install a remote bleeder like this that Peter is suggesting but it’s not essential, especially on basic minis with no servo or heater
IMG_2929.png
I did this too as trying to get at the bleeder with a servo is torture.

Re: Bleeding minis!

Posted: Thu Dec 19, 2024 11:06 pm
by mab01uk
Read this interesting quote below from an old thread while searching for something else:-
"If your brake master cylinder is pulling the fluid back when bleeding the brakes, as most of them do in my experience, you will never get all the air out without a pressure bleeder, it's probably the most useful tool you can buy if you plan a long & happy relationship with Minis!"
viewtopic.php?p=80990#p80990

Re: Bleeding minis!

Posted: Fri Dec 20, 2024 7:21 am
by Aussie Bill B
Had a similar problem recently: lots of pedal pushing but no movement at the slave cylinder.
Pulled the master and slave cylinders apart but everything looked good.
There isn't much else to the system that can stuff up!

Tried to blow through the new flexible hose going from the body to slave cylinder, but it was blocked.

Cleared it with a length of piano wire. Clutch now easily bled by old method using PVC hose
There's always something new to go wrong.

Not saying it is the same issue you have - just thought I'd mention it.

Re: Bleeding minis!

Posted: Sat Dec 21, 2024 5:17 pm
by moita
I have a new slave, hose and rebuild clutch master and got all moving, but seems that something is still wrong as I listen "cavitation sound" when I take the foot quick from the pedal pressed down.