73 Midget Clutch Issues

[71MidgetRebuild]

Hey all, my journey continues. After finally getting the ‘73 midget running, I wanted to take it for a spin to see how the transmission was. I tried to get it into gear but the clutch went straight down to the floor with no resistance so I knew I wasn’t going to go far. I still had to try and or course I could not get the car into gear. I decided to replace the master, slave, and the hose to make sure I knew the condition of everything. While removing the hydraulic hose, I noticed the copper pipe was broken so I replaced that too.

I bought this kit from Moss Motors - master slave kit
I bought this pipe from Moss Motors - pipe
I bought the One Man Bleeder from Moss Motors - One Man Bleeder

I took out then pedal box, brake and clutch masters, and pedals cleaned them all up to new metal installed new brake and clutch masters on the pedal box, and put it back in the car, attaching the old springs to the pedals (I’ve bought new ones, just didn’t install them). I bent and ran the new pipe in the proper place, attaching it to the new hose which was connected to the new slave. I added remote bleeder to make it easier to bleed. All items were installed and all fittings are tight. I added Dot 4 fluid to the master and pumped the clutch, fluid did not move at all from the reservoir on the master. I made sure the bleeder was open and tried again, still no luck. I removed the pipe fitting from the master and pumped the clutch pedal to see very little if any fluid coming out. I eventually was able to get the fluid through the system using a shop vac attached to the bleeder valve until I pulled fluid through. Attached the one man bleeder to the bleeder and followed all the steps this video to bleed the line (when they switched to the one man bleeder). I could get the fluid to go into the tube of the one man bleeder, slightly past the black part of the tubing, but never all the way. Clutch pedal still went to floor.

I followed the steps in this video performing the pushing part 5 times, and not just four as the video suggests. Put the small socket in, pressed the clamp on, tried to pump the pedal (which according to the video shouldn’t move) and the pedal went to the floor. I’m stumped. Is there still air in the system? What should I do now?

 

[fordmstr]

I recently had to replace my 73 Midget clutch master cylinder and had trouble bleeding also. I ended up making a vacuum bleeding jar with a hose that would fit on the slave cylinders bleed valve tightly and long enough to reach down under the vehicle on jack stands to the jar on the floor with the hose going clear to the bottom of the jar on one side and another hose coming out of the jar I could hook up to a hand vacuum pump. Best to have a glass jar big enough to hold 12 ounces of fluid and hoses that are run into the top of the jar lid that fit so tight that you can pump up a vacuum in the jar without it leaking off. I would pump it up into a vacuum and open the bleed valve on the slave cylinder, leaving the bleed valve open. Then push the clutch pedal slowly a few times. Go back and pump the vacuum pump into a vacuum again would start to see bubbles of air come out of the hose that goes to the bottom of the glass jar I'm sucking a vacuum into. Kept doing that while refilling the fluid in the clutch master cylinder, which you don't want to run low. It took a number of times doing it over and over but was getting the air out of the hydraulic system. I had my wife come out and help me, under duress but I needed some help. I closed the bleeder valve, pumped the vacuum pump up so there was a vacuum in the jar, then had my wife pump it clutch pedal a few times and hold it down while I opened the clutch bleed valve to check for any further bubbles of air. She could only stand helping me for about 5 minutes before she was complaining but after her helping me bleed it while putting in a vacuum and pumping up the clutch pedal with the bleed screw closed then have her hold it down while opening the bleed valve a half a dozen times there was no more air bubbles coming out.
I watched both of those videos you had followed, so you aren't the only one to battle this problem. Good luck.

 

[71MidgetRebuild]

I was back at it tonight trying different things I’ve thought of and things people have pointed out. Here I’m bleeding the remote bleeder by opening the bleeder, pushing the clutch in, closing the bleeder, and releasing the clutch. I’m not all that happy with the clutch fork movement I was getting to start this evening. I pushed the pin and piston in on the slave and got better results for a little while, but you’ll see each pump on the clutch gets a shorter movement each time. On the 19th pump in this video, you’ll hear a bang (stick fell off of clutch) and the following 6 pumps are like the first video.

I got to thinking about the remote bleeder and how it seems to always be leaking so I took the top two pieces off and put Teflon tape on the threads just to make sure liquid wasn’t getting through. I then remembered that last night when I followed the instructions of the one video of clamping the socket into the slave and then pushing the clutch pedal that the lid on the master I bought from Moss Motors “blew it’s top”. I began to think this was a pressure relief and there was a small little hole in the cap. I took a ball pump needle and realized it was a little too big to fit, but that is a good thing. I pushed it through, turned on my compressor for ten seconds, put the cap on and pushed some air into the full reservoir which pushed the fluid through the line. Pushed about three 3/4 reservoirs through (with the bleeder open connected to the One Man Bleeder). After doing this, the clutch pedal seemed a little firmer, but still no where near where it needs to be. I’m happy to see there appears to be no leaks as the fluid holds it’s level with the clutch pedal pushed in and kept in as seen here (there are no air bubbles coming up either). I’m going to keep the clutch pushed in overnight /24 hrs just to make sure the levels stay put and to possibly get any trapped air out.

Trying to eliminate questions I have. The picture of the pedals shows where the springs are connected to the pedals and the car. Where the springs connect to the car, should the tab with the hole for the spring be closer to a 45°/90° or is it fine where it is?

I feel I’m getting there but still looking for suggestions here and your opinions. Thank you in advance.

 

[mezy]

When you clamped the slave in. How hard did you depress the peddle it should not have blown the top off the tank.
Wondering if the seal has been fitted the wrong way round. Would be worth stripping to find out.

 

[fordmstr]

The springs look normal to me, just need to be at a slight angle so you can attach them. Not sure how firm the clutch pedal is supposed to be, mine is fairly easy to push down. How much slave cylinder travel of the rod do you have? Have you tried to put it in second gear when the engine is running to see if it's working at all?

 

[Bayless]

I can't say how much slave movement you should have but your videos certainly do not show nearly enough. My Sprite has a 5 speed and its clutch doesn't work either, air I am pretty sure. Also on the first video showing the bleeder, that doesn't look like enough fluid with each pump. With the bleeder open so no back pressure to compress the air I think you should get a lot more fluid. That sounds more like a master cylinder problem. A suggestion though, bleeding any hydraulics can produce a lot of waste fluid. Instead of trying to catch it with a towel, you will have better results with a clear plastic hose from the bleeder to a can or jar to hold what comes out. This gives a second advantage in that you can actually see the air bubbles going through the hose. Next time try opening the bleeder at least a half turn before pushing the pedal to be sure you don't have back pressure and see how much fluid you get. Also, even a hand pumped vacuum bleeder can pull a lot longer stream of fluid than you can get by pushing the pedal once for each valve opening. That can really help in pushing that air bubble through the system.

Finally, a note on blowing the lid off the reservoir with the slave clamped. Under any normal circumstances, that will not help push any air out of the system. It will just compress it wherever it is. Once fully compressed, the pedal will just stop unless it is already down to the floor. I suppose it is conceivable that you could push on it hard enough to cause the rubber cups in the master cylinder to fail and let the fluid pass. If so, I would suspect permanent damage to the rubber.

 

[Bayless]

Did you ever get your clutch to work. If not, I think it sounds more like a master cylinder problem than an air problem.