MG MGB and MGB GT Tech Talk
have been atempting to bleed the slave cylinder on my 79 b have pumped the clutch till my legs were num and then had my daughter pump untill her legs were num and then my wife all i am getting is spitting of fluid bad slave?
STOP pumping! Is the slave new? Is the master new? Is the bleeder in the right place on the slave (top hole?)
Fill the master and let it sit for awhile then gravity bleed. Let it sit. 2 strokes to get some pressure, then crack the bleeder on the 3rd stroke. Tighten immediately. Repeat as necessary but dont pump and create more bubbles.
OR
Bleed from the bottom by pushing fluid in and up to the master. A sacraficial turkey baster will do or go buy a syringe. Push fluid slowly up to master and let it bubble up. Dont overfill!
Rob
thanks rob i'll stop pumping how long should i give the gravity method 1 beer or 2 or just leave open plaese forgive never had a clutch that had this issue before advise much apreciated
Stephen, dont leave it open, all the fluid will run out!
get an empty bottle, you must have several around by now. Put a breather hose on the bleeder and let it run about 5 seconds at a time. Let it sit for a couple swigs of beer and repeat. After that, do the pressure 2 pump from the top.
Good luck
Rob
Dan, it can be used again. But usually it stays in the garage. Sacrafice to the MG gods.
Two people required.
In the driver's seat the pedal should be pushed only half or three quarters of the way down and then only in a slow and deliberate fashion. Pumping the pedal will aerate the fluid and make bleeding impossible.
Under the car you should first open the bleeder a little and use your hand to push the slave rod back up into the bore as far as it will go without too much force. Air and fluid will be expelled. Then, holding the push rod in that position and with the "driver" in position, have her slowly push the pedal down. When about half way you should open the bleeder and allow the air to be expelled before closing the valve. The driver should then release the pedal and the entire effort repeated several times. After you begin to notice little or no air being expelled, on the next go-round you should release your grip on the push rod and allow it to be pushed out by the displaced fluid. Have the driver stop at about the half-way mark and come down again for half a stroke repeating until you can observe the rod moving out against the pressure of the clutch release arm. Once to this point several more slow half strokes should show "full stroke" at the push rod. The movment there should be about a half to three quarters of an inch.
BTW: All of this it a waste of time unless you have insured that the clevis pins and forks at BOTH the slave cylinder and master cylinder are unworn.
Jack
John Twist had a method described in the lastest Driver where he removes the bleeder, covers the hole with a finger and has someone pump down. He then lifts finger, replaces finger, and person in car lets off the pedal. After several of these cycles, the bleeder valve is replaced and then he goes on to use the std method of bleeding. Never heard of doing it that way before, but there is some logic to it.
MGBs are notorious for being hard to bleed; I do it from the bottom.
I used to help out in a garage a few years back and I saw a guy bleed a truck clutch that way
have never used that technique will try next weekend the temp is dripping here calling it a day thanks
hey guys thanx will try again next weekend the skys are clouding and temp is dropping thanks again will letyou know how it turns out
Here is the way i do mine.
1 I cut and notch in the end of a 2 x 1 in by about 3 foot board and fit the notch
on clutch peddle above the peddle pad.
2. I then take the board and push the clutch peddle in all the way then mark the board a couple inches behind the edge of the drivers seat front edge.
3. I pump the peddle a couple of times then lodge the board in with the peddle down between the peddle and the front of the seat bottom.
4. I go down and crace the bleed screw with my thumb over the hole and let the air out and retighten the bleed screw.
5. I repeat 4 several times until there is no air coming out.
6. I repeat 3. but this time i go under the while holding finger over bleed screw I force the clutch lever back toward the slave cylinder and crack the bleed screw until it bottoms.
I measure the compressed distance of the lever arm while compressed then let off the peddle then set the board again and remeasure the extended travel of the lever arm and repeat this till I get abou 1/2 inch travel on the lever.
I had a lot of trouble bleeding my clutch until someone on this forum gave me the answer.
I bought a one pint pump style oil can with a fexible spout. Cut a small piece of hose that fit on the bleeder valve and the tip of the spout. I had to clamp the house to the spout. Drained system and put 3 oz of dot3 in the can and pumped it into the system through the bleeder. Topped it off, pumped the clutch a few times and like magic I had a clutch.
You do have to make sure that the hose and bleeder are in the right spot, I bought a new slave and it came with the bleeder valve in the wrong spot. The bleeder is higher then the hose and I understand that there is a design flaw in the slave that makes it very hard to get the air bubble out so the bottom feed method makes it much easier to get the system bleed.
Cheers,
Larry
Hello to All, I did the same clutch thing today; all new stuff, zero leaks, no pedal pressure.
I was assuming I had "blow-by, or a bad clutch master cylinder that would not create pressure.
So, in a closed system, where does the foaming come from? Is it the air in the master cylinder that must escape and won't if you pump the pedal excessively? Why does this never "clear" itself, because, it won"t, that's for sure! If I let is sit for a couple days, does the foaming go away so I can begin again correctly?
Good News? Did the brake system today and they are great!
Thanks, Doug.
Actually Chris, that IS a very good way to do it. I hesitate to suggest it to folks though because I can't figure out how to describe the nuances. I would suggest that the bleeder NOT have to be fully removed, but only undone about a half turn or so and the finger tip applied to the opening. There is little chance of pulling enough air back into the system by way of the threads and what does get in is quickly worked out.
This was my preferred method when working with Spridgets. Back in the olden days when I was considerably more slim I could drape myself over and around the gear lever and work through the opening in the passenger foot well while pushing the clutch pedal with my toe. It has been years since I had the pleasure and I am not sure that my tummy would allow such contortions now. LOL
Jack
push bleeding is the easiest and a 1-person process.
with the bleed screw in the bottom hole!!!! push juice in until you fill the master.
I'd not try a turkey baster, you need a little more pressure than that....I'd be afraid of the bulb blowing off. (but if it works for you, that's ok by me.<G>)
While on this topic, i would like to know how far you have to push your clutch pedal to get a release. I have to push my clutch to within about an inch or two of the floor. Is this normal or should it release a little higher up?
Ken
Check your clevis pin and fork conditions. It only takes a tiny bit of wear in either one to account for extra slop at the pedal. If that doesn't bring the release point up on the pedal you might be looking at a well worn release bearing.
Jack
The bleeder valve is shipped in the wrong location due to packaging concerns. The system is difficult to bleed because of the hump in the hardline coming out of the clutch master. Air likes to stay there.