Bleeding Brake Problem

[Ashman]

If you guys do it that way then that's good enough for me.

[untakenname]

I find the best and easiest way to bleed the brakes is to use a vacuum extractor, I use a twenty pound oil one not a specialised brake bleeder but it works on the same principle.
Takes less than a minute to bleed the system after replacing a caliper compared to ages when doing it by pumping the pedal.
You can also get speed bleeders that have a one way check valve which work quite well.

[Ashman]

I have bought a hand held vacuum pump kit, it hasn't arrived yet.

The speed bleeders are a good idea, i may get some in the near future and keep in the car for the next time i do the brakes.

[Freeman38]

Just a one man bleed valve is all you need.
Then you can just sit and pump the pedal, and just check for no air in the clear tube.
I always do the furthest point from the reservoir which would be the rear left first.
Then the rear right, front left, front right.

[ChrisHolmes]

When I fitted Dave2112s braided hoses I put cling film on the master cylinder and fitted the cap just a fraction of a turn to seal. The fluid then hardly drips out of the system when the unions are undone.

[Ashman]

Now i'm 100% certain i's a master cylinder problem, i'm going to order a repair kit and see if that helps. There's absolutely no air in the system now so i can only assume it's not holding pressure.

[13Black]

It might be there was some grit or corrosion further down the master cylinder stroke and the pumping action has torn the piston seal.

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[Ashman]

The car was parked outside the Mazda dealership for at least 18 months, could've been even longer before they got hold of it as a P/X.

[Ashman]

Ok i'm not seeing anywhere to buy a seal kit. Anyone have any ideas?

[qwakers]

i have a spare pz master, worked when it came off.....

[PeteH]

Apparently they almost never need rebuilding. I know because I once asked Clive at MRP. You should be able to buy the individual seals from Mazda (or Clive), but be sure it's definitely what you need.

An easier solution would be to buy a used master cylinder from a breaker like Bigpete. They are reliable bits, so second hand should be fine.

Edit. Or qwakers!

[Ashman]

I'm thinking a second hand master is the way to go, i can always replace down the line but getting it on the road is more important atm.

i have a spare pz master, worked when it came off.....

How much with postage mate?

[qwakers]

£25?

[Ashman]

pm'd

[Ashman]

So i bought the master cylinder from qwakers and i'll let you guys know what happens. Fingers crossed it works and i can get the car mot'd and on the road

[nightfire10]

I tried brake bleeding using the 20psi system today but leaked like a pig so would like to buy a master cylinder cap to reuse
Cheers Steve

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[qwakers]

I tried brake bleeding using the 20psi system today but leaked like a pig so would like to buy a master cylinder cap to reuse
Cheers Steve

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i tried that it doesnt work

[warpc0il]

The way the lid locks means that it can't form an airtight seal, and it's not meant to in normal operation.

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[nightfire10]

Must be a lid that will lock ?
Cheers Steve

The way the lid locks means that it can't form an airtight seal, and it's not meant to in normal operation.

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[qwakers]

nope. ive tried everything even as far as machining my own lid in a lathe. no go. no matter how tight it is, the way the lid fits means you cant get a positive seal.

[13Black]

My darling sweet peas.

You don't need a 100% airtight seal for a pressure bleeder to perform its function successfully. You just get a slight pressure drop.

Perfect is the enemy of good.

[nightfire10]

I've no lathe but sounds like a challenge

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[qwakers]

My darling sweet peas.

You don't need a 100% airtight seal for a pressure bleeder to perform its function successfully. You just get a slight pressure drop.

Perfect is the enemy of good.

you do with the gunson kit or you just pour fluid all over the place.

[nightfire10]

My darling sweet peas.

You don't need a 100% airtight seal for a pressure bleeder to perform its function successfully. You just get a slight pressure drop.

Perfect is the enemy of good.

Nick at 20psi from my motorcycle tyre it pissed out of the cap ! Didn't know the brake lines were held with captive nut brackery when I was challenged at mazda Bristol quite annoyed as I did both in 30mins today but 3hours to do one pipe change and bleed in Bristol lol

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[nightfire10]

To be fair it's a loooong time since I've replaced a brake line ! Or had to

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