MG Midget Forum

I installed a new slave cylinder in my 76 Midget. I did so from underneath the car. Here is the procedure I used:

First, I removed the cover plate shown in the attached photo. Then I was able to slip the push rod (item 20 in the attached parts diagram) over the pin (item 21 in the attached parts diagram).
I then
(1) replaced the cover plate, and
(2) installed the slave cylinder by
(a) making sure the push rod went into the hole in the center of the rubber grommet at the end of the slave cylinder and
(b) pushing the slave cylinder all the way in as far as it would go and then
(c) tightening the pinch bolt.

I then bled the slave cylinder three different ways and I am 99% sure that each way I bled the slave I eliminated all of air from the system. During one of the ways I bled the system I watched the air bubbles leave the system. I also reverse bled the system to the point where the master cylinder was filled with fluid.

Nevertheless, I still do not have a firm clutch pedal.

Did I install the slave cylinder correctly? Why do I still not have a firm pedal?

Thanks for your help.

mbjg0788

If I had a dollar for every "clutch won't bleed" post...................



Edited 1 time(s). Last edit at 2014-11-23 11:00 AM by 76mgdriver.

John,
Didn't know you were still struggling...
All I can say is keep bleeding. Even the most microscopic amount of air will cause failure.
If you're feeling any resistance at all you're probably all right mechanically.
Bleed screw is on top right? I also have an EZ bleeder on mine which is basically a check valve.
They're available at most auto parts stores. It sounds like you're close so I wouldn't do anything other than bleed bleed bleed right now..
I remember having to kick my pedal hard and fast to dislodge pesky air bubbles.
Good Luck, Mike...PM sent.

John - I Just went through this on my son's 76. In fact, I just got back from the test drive after finishing the job. When I first replaced the slave (along with the master and connecting pipe/hose), I did what you you said and it was very mushy. We pushed the pedal to the floor with a 1x2 and clamped it to the steering wheel so that it stayed down all night. In the morning, there was enough pressure to get it into gear, but it wasn't right so I went back through all the posts and how I had done everything, and concluded that there was still air in the slave. When you install the slave and feel the pushrod is in the right place, unless you've somehow pre-filled the slave, there will still be air in it. The pushrod won't push out the air. You may be able to get it out by bleeding again and again, but I hate spending time under ours with my nose pressed up against the bottom of the car so I decided to pull it out again and bleed it while the slave was tilted up so I knew I'd get all the air out. That's what I did last night. There is much more resistance pushing it in against the pushrod that way, but after a lot of sweat and gunk falling in my eyes (broke my glasses earlier in the procedure) it went back together. The pedal was still soft, so I repeated the 1x2 trick last night, and presto - this morning I had great pressure and it shifts great (I also changed the transmission oil).

Good luck with yours - you may just need to keep the pedal down overnight, that's worth trying unless you're determined to drive it tomorrow.

Adrian

Thanks much Mike and Adrian.

Mike and Adrian, could you please look at the attached photo? Do I have the pushrod installed in the right location? If not, here may lie my problem.

Thanks.

John

That is incorrect. The push rod end needs to be centered, not off to the side like that. I imagine even that little bit of offset could be contributing to your problem. These clutches are VERY sensitive to wear in the mechanical linkages and even a few .01's off will give you a "no go" situation. I struggled with worn linkages on my '67 GT forever before figuring out that was the issue, so your offset push rod should be fixed and then test your clutch again.

-David

John,
It goes in the lower position with the red arrow...
Now you should be good to go!!

Looks like I'm too late - by now you've probably already fixed it! Good luck, get out there and enjoy the November thaw.

Thanks to all.

Yes guys, I fixed it and put it where the red arrow is, but I still had soft pedal after bleeding the system.

I am going to try keeping the pedal down overnight. When you kept the pedal down overnight, you left the bleeder valve cracked open, correct? and while the pedal was down overnight, to what extend did you have the slave and master filled with fluid? As it stands now, my slave and master are filled

John

noooo - the bleeder valve should be closed. The idea is that the pressure forces the last of the bubbles up to the air space in the master, but some of those tiny bubbles (cue Don Ho) take a long time to make their way to the top. I don't know if they're all actually gone in an hour, 2, or 3 (I would guess it's all done in the first few hours) but by morning they will be gone and I predict a noticeable improvement. Just do your normal bleed routine first. I saw the overnight advice in another post, followed it and it worked for me. Now that you've got the pushrod issue fixed, you may not even need this step but if the pedal is soft, I think it's worth a shot. If nothing else, it forces you to leave the #$%# alone for a few hours. Sometimes that's all it takes.

When I bled the brakes and clutch on my Ducati it was easier because the last few inches of the system before the master cylinder were clear tubing and once I saw the bubbles stop I knew I was done. On the Midget I just installed a VB replacement tube which is red but translucent, so I guess you could do the same thing if you shine a light behind it and look for bubbles, then test it when you haven't seen anything in 30-60 minutes. It really is a small system so overnight is probably massive overkill, but I was happy to just leave it overnight. If you get done early enough in the evening, you could try it for an hour or two and then check it.

Good luck - after a frustrating few hours dealing with this, it was a great relief to have it finished. I hope you're back on the road soon.

Adrian

Yes he is. He sent me a long series of emails that did little more than confuse me. Some of them even made it sound like he was attempting to bleed the clutch with the master cylinder removed. I tried to help but he just got mad at me. Said something about how I needed to be more humble or some BS like that. Would have been nice if he tried a little harder to effectively communicate. He may be beyond helping honestly.

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Seth Jones

1971 MG Midget

www.SpridgetGuru.com

Down Boy!!! Deep Breath!!!

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Webmaster, The MG Experience
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I had problems getting all of the air out of the clutch slave cylinder on my '61 midget. I ended up bleeding the slave by letting it hang down so that the bleed screw is DEFINITELY on the top of the cylinder! Have to be careful of course because the pushrod is not holding the piston in place. When you've got all the air out, bolt it back into place and reinstall the pushrod etc. Worked for me!

IanF.

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MG Midget MK1 (1961)
MGBGT (1972)

I just did a 65 a few weeks ago. Not as bad as the 73 with contaminated clutch fluid I did the previous summer (owner tried using 20 w 50 instead of dot 3). You can reverse bleed the clutch on a 61 or 65 pretty easily. Just connect the bleeder screw on the right front brake cylinder to the bleeder on the slave (with some clear acrylic tubing), crack both bleeders open, pump the brake, fill the common reservoir, pump the brake some more. This will fill the clutch line, and prime the master all in one fell swoop. gets most of the air out too. Next close both bleeders. Pump up the clutch. If it's still spongy, thats because there is a little air in the slave. Open the bleeder, and press the piston in as far in as it will go, Close the bleder. have a friend pump the clutch a few times. Crack open the bleeder and press the piston in. Worked for me anyway.

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Seth Jones

1971 MG Midget

www.SpridgetGuru.com