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MG MGB Technical - Need Your Help... clutch question

Good morning... need your help with this please.

I have a 1979 MGB (Roadster). Yesterday while on a little road trip I stopped at a light... and, well a "Rice-burner" thought he could beat me when the light changed... I did out shift him and stayed ahead until I hit 4th gear... still in town so I let him go by.

Now, here is my question: a little later after I stopped at the store I went to, I noticed when shifting there was a "feeling" like the clutch pedal was hesitating to come back up.

The clutch pedal has always seemed rather soft when pushed down. (I have owned this MGB for 9 years, and it has always felt soft, so nothing new) I've had many other cars (american made) with a clutch and they have always felt like there was some pressure required to push down.

I checked the diagram (page 127 VB) and noticed there is "suppose" to be a Return Pedal Spring.... not there, cannot find it anyplace... there is one on the brake, but not on the clutch...

So, my question is this: could the spring on the master clutch cylinder be what I have been using all this time? (part #9 pg 127 VB) Would this account for the soft pedal feel?

The clutch doesn't slip, transmission shifts great...

I now have on order the required spring (and new pedal pad set).

Looking forward to your thoughts.

Enjoy your day!
Don 1979 MGB
Don

You will feel a little more pressure at the pedal although not much. The bad part about the spring missing is that it can allow the weight of the pedal to put some pressure on the master cylinder, this may or may not cause the throw out bearing to remain in contact with the clutch. This can shorten the service life of the bearing.
John H

There should be a pedal return spring on both pedals, and this is primarily to ensure the master piston fully returns and clears the port into the reservoir. The design of the hydraulic system is such that there is a spring in the slave cylinder which does keep the release bearing pushed up against the cover plate, this is part of the self-adjusting mechanism, and ensures a consistent biting point over the short term i.e. crankshaft float doesn't push the piston further into the bore resulting in a low biting (or more correctly release) point the next time the clutch is operated.

I'd have said the MGB clutch would feel *heavy* compared with modern cars, as John says the pedal spring won't add much weight.
Paul Hunt 2

Hey thanks John and Paul for getting back to me.

When I was referring to having american made cars with a clutch (opps, show my age here), I had a 46, plymouth, 54 Ford, 54 Merc, 53 Chevy, etc.... but that was back in the 60's... and you knew you were pushing in a clutch.

So, when I get the right spring on the pedal, then I should feel it right?

My daughter had a Saturn that had stick and the clutch was very "light" compared to the older cars I had before. (This is what you meant Paul?)

Enjoy your day!

Don
Don

Don,
nearly everything has been said, so i can only add some words to the different feeling between the B and larger cars you have compared.
If you feel the pedal of the 1800 MGB 'soft', it is due to its small clutch mechanism compared to larger cars, when i have driven my BGTV8 (3.5 Rover and 5-speed)and then change into my B 1800, it's clutch actually feels soft. Compared to my son's BMW 1800 it is a little heavier to push the MG pedal down.

Paul pointed out something interesting concerning the spring and the port to the reservoir. It might be, that fluid is only delivered insufficiently when the spring is missing and if fast gear changes are made, it might occure, that you run short of fluid supply.

Fit a spring, top up and, for pice of mind, have the system bleeded.

Ralph
Ralph

Great help Ralph!

I've never have "bleeded" the clutch system... guess I'd better do some reading before I get the spring to figure out how-to-do-it...

Last Fall I had some brake work done (professional), installed new rear brake adjusters, new braided hoses and he bleeded the brakes at that time... work great..

So, is it a "simple" task to bleed the clutch "or" should I have it done by a professional??

Have a GREAT day!
Don
Don

Don,
if you did not have had bleed a cluth system before, just have it done, it is a job of a few minutes only, if the car can be lifted, otherwise it can be a nightmare if you try it on the road for the first time.

Ralph
Ralph

Don, any car with a hydraulic clutch takes much less pedal pressure than the old american iron with mechanical linkage. Even the motorcycles have gone hydraulic. I guess I'm old two as I had some of those cars.I had a friend with a 66 GTO and a heavy duty clutch, if you had to hold it down for any amount of time your leg would start to shake from the pressure required.
John H

John, that was the way my 54 merc clutch was, almost needed both feet to push it down. I had a 57 "T" Bird engine, with a 4 barrel carb stuck in that 54 merc.... really moved down the road once you got it rolling!

Ralph, I will look up what it takes to bleed the clutch... I am kind of "old school" if it's working, leave it alone..... might just use it, it's not broke, just needs a spring to make it return better.

Thanks to both of you, enjoy your evening!
Don
Don

Bleeding the 'normal' way is a right pain by all accounts, so much so that when I replaced my master, slave and flex hose I didn't even bother to try but used a gunsons EeziBleed connected to the slave nipple, and very low air pressure, so reverse fill the system, and got full travel 1/2" to 5/8" straight away. Since then I've seen two other methods mentioned - one is to clamp the slave piston into the bottom of the cylinder for bleeding (there is normally a significant gap), and secondly to interconnect the slave and a caliper nipple (the two are the same size) and use the brake pedal to reverse fill/bleed the clutch.

Last week I had the opportunity to try both on a 'barn find' where pedal bleeding just produced lots of gurgling but only a few splashes of fluid. Clamping the slave piston into the bottom of the cylinder had no effect, but using the brake worked a treat! I siphoned the fluid out of the master first, then pumped enough through to fill it. This was on a 78 with large transparent brake master reservoir so no chance of running *that* out (and having to then bleed the brakes!) and it hardly lowered the level. Also only pump the brake pedal gently or you will blow the hose off.

Using the brake system to bleed the clutch like this is so easy, easier even than using the Gunsons in reverse mode, I wouldn't bother doing it any other way in future.
Paul Hunt 2

Forms of the verb, to bleed:

present - bleed
past - bled
past perfect - have bled
participle (all tenses) - bleeding

English Major

Thanks to the non member for stating the bleeding obvious. I found that one of my pedals was missing the return spring years ago as result of the collective wisdom of this board. I fitted one but it's absence had never caused a problem.
Stan Best

Well I think we should welcome Mr English Major to the BBS as he will be here a while if he wants to correct all of our spelling errors. I am just too lazy to sign in so I guess im a (non-member) at the moment as well
James

James,

Yes, i have registrated myself some time ago in this board too.
But i also do not sign in here, as it also works this way, but sometimes i wonder whether some of the visitors have realised that 'MG' is spoken here.

Dear English Major, i learned this language after buying my first MG by reading the workshop manuals and listening to the radio, what would you think upon such comments in an Italian MG bord, or a Dutch MG board, a French, a Novegian, a German, a Spanish ... these cars have a community all over the world and there is a kind of understanding each other without strictly right cojugations.
-> Entschuldigen Sie bitte Herr English Mayor, ich möchte Ihnen natürlich nicht zu nahe treten, könnte es sein, dass ich etwas falsch vertanden habe? <-
(-> "I am very sorry Mr. English Mayor but i did not want to blame you. Might be i was not able to realise what you are meaning?" <-)

Ralph
Ralph

Ralph ---

I admire anyone who is multi-lingual. As a victim of six colleges plus graduate school, I had to endure useless Spanish (Castillian --- would not work south of our own border); German (high, not spoken nor used in newspapers) and French (which I found had numerous dialects). And about all I can reember is "Benjo?" if I am trying to find a privy in Japan.

As for our English major, please speak in the past pluperfect tense.



Dan Robinson

James,

You make a good point, but I feel that people who appear to be native speakers are very likely to take offense at being corrected. In fact, my wife, who was an English teacher, avoids telling people this, because then they often say they'll have to watch their language around her.

Ralph,

Thanks for your understanding. I'm sure you know much more German than I do. If I were writing on a German bulletin board and some Germans began mimicking my mistakes, you might even feel that you could help me by sharing the correct spelling of a word. Unfortunately, many on this board seem to feel that correcting language is an affront. I meant no offense, and I hope everyone will forgive and forget and return to MGs.

Stan,

"It's" not that obvious. Oh, I'm sorry, I just couldn't resist. Forgive me, Stan.

EM.
English Major

EM,

i can understand this quite well, of cause and hope that i did not make anyone angry with my answer.

You see, 'Safety Fast' is not only the old MG slogan, it seems it might had been a vision for internet chats of today too...

Ralph
Ralph

Ralph. I lived in Germany for three+ years and neither my written, nor spoken, German was as good as your written English. You do fine, express your views well, and have made a significant contribution over the years. Keep it up.

Les
Les Bengtson

English Major

You might visit a lesson on the use of commas!
Roger T

WOW!.... not only did I get advice about my "English" MGB.... but also advice on my "English"...

Thanks,
Don 1979 MGB
Don

This thread was discussed between 12/06/2007 and 23/06/2007

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