J

joefuller

Member
Hello all,

Had massive dramas with the hydraulics on the S2a recently. First the clutch master cylinder started leaking so we replaced that, then the increased pressure caused the brake master to do the same. We replaced that this weekend. Original was a CB type but a CV type came so we made a new pipe and fitted that anyway. Bled the system at all brakes until no bubbles. When the pedal is pressed it goes to the floor and needs a couple of pumps before anything happens, but then provides very good pressure but then goes again almost immediately. There is a servo and everything was working fine yesterday (apart from the leak). Any ideas what we need to do?

Thanks all.

Joe
 
Back all the adjusters off so the cyliners are fully retracted then bleed and keep the bleed tube submerged. Then adjust up to the right setting. I now use an Easybleed so I can do it on my own and it cuts out the problem of sucking air back in as its a postive pressure in the master cylinder.
 
Have you got the gunson jobbie? I picked one up a while ago but haven't got to use it yet. Slightly daunted by all the bad stories with bleeding series brakes, particularly TLS, and I'm not really sure what to do with the kit. I'll probably end up strangling myself with it or something equally daft.
 
I had to pump my series brakes when I first got it, I tried belle ding but made no difference. When I took the drums off I found the adjuster were seized and the shoes needed adjusting. I put new adjusters and shoes on and it was good after that. If the shoes need adjusting it takes a couple of pedal pumps to push the onto the drums. Raise each wheel and adjust until they are just slightly rubbing the drums.

Col
 
Pressure bleeder (as said above) or one of those vacuum suckers - you can even do reverse bleeding with the Gunson eezibleed kits which (so long as the system has been cleaned / darined / rinsed through) will help push air back up top - keep an eye on the fluid coming out of the top though...
 
I've heard reports of slave cylinders being fitted upside down, might be an idea to check that. The bleed nipple should be on top.

Col
 
Clutch slave can be fitted upside down brakes cannot due to shape of back plate hole.
 

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Yes, after I posted I wondered about the logic of what I said and I'd like to retract it. However, I have read somewhere on here about something with a bleed nipple being the wrong way up, maybe it was a clutch slave cylinder.

Col
 
I've just replaced the servo, master cylinder and all the front cylinders on my series 3. I used an Eezibleed without any issues. The only problem was that it took a while to get the master cylinder primed. Having looked at the forums after the event there does seem to be various ways to do this. I've still got to do the back slave cylinders so we'll see if the methods described make it easier.

Having got the master primed I did several goes at bleeding, i.e. front to back cylinders in sequence before I got a good solid pedal feel, but I got there in the end. Remember to adjust the adjustment cams as well.
 
Backing off the adjusters really helps as it pushes the pistons fully into the cylinders and leaves nowhere for the air to hide. Really helps on the TLS fronts as you are bleeding from the bottom.
 
Thanks all for the advice. We have tried bleeding twice now and moving the adjusters till the jacked wheel stops turning and backing off a little, and you still have to pump the pedal to get firm braking, which then disappears after a few seconds. Dad thinks the servo may need bleeding. Is this right and how to bleed it if so?

Cheers all
 
Clamp the flexies and test the pedal then.
If good, release one at a time until the symptoms reappear on the dodgy axle.
Never tried this because I've never had brake bleeding issues , just something I've heard can help and it seems logical to me.
 
The sequence is back the adusters right off so the wheel is free and the springs pull the shoes / pistons into the cylinders, then bleed furthest to nearest keeping the bleed tube submerged in the fluid in the jar (and don't tip it on yourslef...) then adjust each brake up to just free, this take a few goes as you have to adjust, pump the brakes and adjust again. I go for a drive and take the spanners then check the drum temps (by hand, but be careful!). If you do all that and it still takes a pump you need a new master cylinder, not a big job and it happens quite a lot. And watch out for pitfalls like adjusters that slip over the pin, replacements that turn the wrong way etc, they are all out there....
 
Is the replacement master cylinder the same bore as the original?
Where the ports the same orientation?
 
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