T-Series Clutch pedal slow to rise

[A. Claffie]

I'm slowly making progress on resurrecting the derelict MGB I bought in 1987, drove for 10 years, then put in a barn until last spring. It turns over and will probably start with fresh gas, and it has brakes on three wheels. That's not bad.

The next hurdle to overcome is the clutch pedal. I push it down and take my foot off it, but it's slow to come back off the floor. This is not the first time this car's had this problem but I don't recall how dear old dad fixed it way back when. The clutch master cylinder has fluid in it. Where do I start?

 

[SilentUnicorn]

Try replacing the rubber hose to the slave cylinder.While it may appear fine on the outside the insides break down, swell up and cause blockage. As good as anywhere to start.


m

 

[JPSmit]

Stupid Question maybe but how is the return spring?

 

[MikeP]

Could also be rust/dirt in the pivot point. You'd need to remove and clean to fix that. Between it and the previously mentioned spring, one or both of them is the culprit since the pushrod isn't physically attached to the master pistion so nothing in the clutch system should prevent it's returning to normal position.

 

[Billm]

Sounds very likely that the pivot bolt is rusted up and the peddle itself is having trouble moving on the pivot. Need to pull out the bolt and clean it up. Unfortunately I will bet that this will require you to pull the master assembly first (it is on the Midget and I think that the B is the same). A real common problem that few people fix and then they have hydraulic problems all of the time.
BillM
-ah a virtual "double post"--

 

[Bob Claffie]

I seem to remember replacing the flex hose once upon a time. When you say it returns slowly are we talking about it coming back steadily but slowly or taking a many seconds to come completely up top ? It could be corrosion on the spline shaft the clutch disc rides on and will "cure" itself over time. Look over the pivots but don't commit to digging deeply YET. Pa

 

[PAUL161]

If everything is in order, clean shaft, good spring, no other obstructions, then all left is the hose. This might not be your problem, but it can happen, where the hose, if old, can start to separate inside and cause a one way valving effect. I had this happen on a front brake hose, noticed when the caliper wouldn't release properly causing the one brake to drag. Not saying it's your fix, just a possibility. PJ

 

[Lynn Kirkpatrick]

When the pedal is on its way up, can you put your toe under it and wiggle it? If it wiggles, the hose is probably collapsed, or either the master or slave are pitted/seized. Is the fluid clear?

Does the pedal go down tight? Lots of drag? I can't imagine the pin the pin being so tight that it can overcome the return force from the clutch fingers.
Let us know what you find.

 

[A. Claffie]

Fluid is clear, pedal goes down fine with little drag (feels "normal"). Problem is most likely hydraulic rather than mechanical if that makes any sense.

 

[Bob Claffie]

Ok, since that replaced hose is close to twenty years old , regardless of the use or lack of, it's time. English rubber goods are the pits. On my silver blue AH, one of the brand new radiator hoses failed from old age having never been driven or pressurized. Change it but be prepared for months of bleeding exercise. Pa

 

[CZ_Dave]

If everything is in order, clean shaft, good spring, no other obstructions, then all left is the hose. This might not be your problem, but it can happen, where the hose, if old, can start to separate inside and cause a one way valving effect.

Yup, I agree, just bought two,
one to replace, and a spare
just in case for any other
cars I may be working on.
They DO go bad

 

[DrEntropy]

Hoses first. They will "valve", causing no end of problems. Rule out th' "silly stuff" first.