MGB 1978 MGB clutch is out..!

[Bendure]

Yes full and very clean. Nothing even gurgles or moves around peddle in/out line cracked or closed. Looks like a little tougher to r&r the master cylinder vs the slave.

 

[bobhustead]

Is the master cylinder piston moving when you push the pedal? Seems like you need to replace both master and slave.
Bob

 

[Bendure]

Yep piston rocks back and forth.

 

[DrEntropy]

Well, as I posted back in #2, replacing M/C, slave and flex line at one go will eliminate any issues. And as Grantura mentions later, keep the old ones and have them re-sleeved if you intend to keep the car.

All a pain in the butt, but a guarantee the issue is resolved.

 

[DrEntropy]

And be aware of the clevis pins, too. Here are some "Wall-of-Shame" examples of what NOT to put back in place. The far right one is extreme, but it happened:

 

[Bendure]

Thanks for the responses. Will let you know how the removal of the master cylinder goes!

 

[Bendure]

Got the master clutch cylinder removed. Easier than I thought.

 

[bobhustead]

When you put it back, do yourself a favor and bench bleed the new master. Just cover the outlet with a finger and work the piston until fluid squirts out. And when doing the replacement be sure to water wash all fluid spills off the paint immediately.
Bob

 

[Bendure]

New master cylinder is back in. Also replaced the flex line - but have a leak trying to connect the flex line to the hard line. Very difficult to see or find a good fitting tool to back off or tighten the tube nut (20 below ) or the lock nut below it (21). Probably lots of air in the system now. The good news I could see a bit of movement in the slave piston. Down this rabbit hole again! After looking at the hard line - looks like it may not be too tough running a new one from master to slave.

 

[DrEntropy]

Save some grief and get a couple line wrenches. SAE, 7/16" amd 1/2". A well stocked NAPA store will have individual ones. Likely better quality than these but if you intend to keep the MG it will come in handy. Likely you need not replace the steel line.

Double-End Metric Flare Nut Wrench Set, 5 Piece

Amazing deals on this 5Pc Metric Double-End Flare Nut Wrench Set at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

EDIT: The flex line may be 5/8" at the fittings, I don't recall.

 

[Bendure]

Save some grief and get a couple line wrenches. SAE, 7/16" amd 1/2". A well stocked NAPA store will have individual ones. Likely better quality than these but if you intend to keep the MG it will come in handy. Likely you need not replace the steel line.

Double-End Metric Flare Nut Wrench Set, 5 Piece

Amazing deals on this 5Pc Metric Double-End Flare Nut Wrench Set at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

EDIT: The flex line may be 5/8" at the fittings, I don't recall.

 

[Bendure]

Thanks Doc! Any idea what the lock nut is below the tube nut? Things broke loose after tons of blaster. But I could feel the line and mechanism turn a bit above the flex hose while trying to break everything loose with a vice grip. Ugh!!!

 

[JPSmit]

Thanks Doc! Any idea what the lock nut is below the tube nut? Things broke loose after tons of blaster. But I could feel the line and mechanism turn a bit above the flex hose while trying to break everything loose with a vice grip. Ugh!!!

If it is what I think it is, it is to hold it on the bracket

 

[DrEntropy]

Well, the way it was designed to work is the bracket on the frame holds the end of the flex line via that nut from the "top side" so you can tighten the steel line's ferrule to it. If the bracket and/or the line fitting have been rounded and buggered, Vice Grips to remove and replacement ferrule may be the only option.

 

[Bendure]

Hello All,

Looking for any new help with my 77 MGB clutch problem. Replaced both master and slave and flex hose. It appears most air has been bled out successfully. The slave piston only travels maybe a 1/4". Just watched a video from moss on evacuating air out of the slave. Will try that next

Questions - What is the actual travel distance for the clutch piston?

Thanks!

 

[Bendure]

Follow up: lots of air came out trying this method like the whole system is full of air.

 

[JPSmit]

Follow up: lots of air came out trying this method like the whole system is full of air.

has it worked? The reason I ask is that it took me almost an entire summer to sort my clutch a few years ago - NOTE it is a different line!!! - But what I finally realized is that my new clutch line wasn't seating properly hence the ongoing air issues. It wasn't seating properly because it was made of chinesium. I finally found a hose (again the Midget line is a plastic) and reused the original ends - finally fixed it. I find that there continue to be massive issues with a lot of the new parts being speced to the lowest bidder.

 

[Bendure]

No luck yet. Using the original hard line and fittings all seem tight. Replaces the flex line, the mc and sc. admittedly knock off parts. This time I followed the gentleman’s advise:

Cannot seem to remove all the air and never get a complete clean stream.

 

[Bendure]

Good news bled like back in the day; open, pedal down, close, pedal up…repeat. Just had to top off the master cylinder about every 1 or 2 bleeds, it holds soooo little fluid.

Thanks for the help!!!

 

[JPSmit]

Good news bled like back in the day; open, pedal down, close, pedal up…repeat. Just had to top off the master cylinder about every 1 or 2 bleeds, it holds soooo little fluid.

Thanks for the help!!!

love it when a plan (finally) comes together