In our case we had just replaced the hose the prior week when diagnosing this problem so we removed the hose from the master cylinder end. The main reason is the 914 is a much lighter car and would have outperformed the 911! Before sending the car to the welder we removed the driver's seat, carpet, and loosened the steering wheel so the welder could have room to work under dashboard. Then you can bleed it normally. It was miserably hot, and it would be an understatement to say that I was frustrated. Follow the blue braided hose from the brake fluid reservoir and that will lead you to the clutch master.
Note that we are only performing one step at a time for a reason. Reinstalling the master cylinder was easier then expected. Turn the pushrod clockwise to tighten till it barely contacts the master cylinder, then counter clockwise one or two turns doesn't have to be exact. Specifically, when you depress the clutch pedal, a rod pushes on a piston in the master cylinder which in turn transfers fluid to the slave cylinder, pushing the slave piston in outward against a lever which in turn disengages the clutch pressure plate. These type of comments add so much to the Pelican tech community.
Even though this hose was designed to far outlast conventional rubber hose, nothing lasts forever. Once the Bolts are tightened to about 18 ft lbs you can tighten the compression nut and the bleeder screw. This is the method I used on my daily driver when I replaced the slave and master cylinders and it worked great. Barring that you'll need to find a way to at least get enough fluid into the system that it can be pumped up with the clutch peddle. Most of the brake fluid blasted onto the windshield.
When replacing master and slave, most people also replace the half-hard line top one in the photo below. These two combined, are what do the most to deteriorate the system. The sleek looks and smooth control of the Porsche make errand running more exciting. Normally master and slave cylinders are shipped with caps in the orifices to protect the innards from contamination prior to assembly. Another common, and sometimes overlooked, problem with 944 clutch system is when the mounting area around master cylinder begins to fracture.
If it doesn't, the master or the salve cylinder could be faulty. This is why regular fluid change intervals are recommended, and increased intervals are recommended if you live in a highly humid climate. There is one hard line and one half-hard line. Brake fluid is an obvious choice because of its unique properties and its parity with the braking system. Check the operation of the clutch so that the clutch begins to engage about an inch or better off the floor. After turning the hard line connection 12mm flare wrench , it was loose enough to hand-unscrew. When replacing master and slave, most people also replace the half-hard line top one in the photo below.
This has the added benefit of letting you watch the fluid in the jar as you bleed the system, protecting your eyes from accidental spills. As always, if you have any questions or comments about this helpful article, please Comments and Suggestions: R Jones Comments: My 89 944 S2 with 34000 miles hard to shift through the gears clutch does not slip any suggestions as to what could be the problem July 7, 2017 Followup from the Pelican Staff: have you inspected the shifter? I replaced with a used slave cylinder. What am I doing wrong? Even an air bubble smaller than a pea can disable the clutch hydraulic system. I felt under the rubber bellows and it was wet with brake fluid. This only takes a couple minutes and makes your life a lot easier. Both work as I used them on two different 944s.
This time, I used a pressure bleeder followed by some manual pumping. Use of anything other than this specially designed wrench will most likely result in a damaged fitting, unnecessarily complicating this task. Once the new slave cylinder is ready we can quickly remove the old one and replace it with the new one. Leave the car alone checking the reservoir and re-filling it as needed for a week or so and gravity will bleed most, not all of the air out. For the other stud left hand side in the picture above , I glued the washer to a screwdriver-tip with a bit of grease and was able to stick it on the stud.
This process is most effectively done by submerging the master cylinder in fresh brake fluid and pumping the piston with the pushrod till air bubbles cease to exist. Brake fluid is special because it is fairly dense, resists boiling at high temperatures, and is kind to the rubber seals used in these systems. I tried pumping the clutch while expelling the air but after 30 minutes with no improvement we gave up. Your vehicle's Porsche Master Cylinder occasionally has multiple secondary cylinders to distribute braking power among the brake rotors. The clutch pedal goes to floor and doesn't come back.
In this case it doesn't matter if you pull out the plastic elbow from its rubber socket since your new master cylinder will include these parts. I suspect that if you are reading this, you are probably questioning the notion of reliability though. Place the master cylinder into position, but don't nut it down. In any case you will need to bleed it to be sure all the air is expelled. Use you line wrench again to secure the fitting. Pic 6 Now we can start by removing the blue feeder hose from the master cylinder. If all the preceding was done correctly you will have little to no air remaining in the system such was our case.
Well, today I finally set up shop and got to work on replacing everything. I tried the pushing brake fluid through the slave valve, but it just seems to block there and not go through the system. We also used a heat gun and screwdriver to loosen the sealant from around the area to be welded. I stuck the nut in my 6-point 13mm socket and that went on easy as well. As a consequence of the hydraulic pressure, only a slight force in a to the Porsche 944 Clutch Master Cylinder results in a large degree of reciprocal force in the transmission's slave cylinder. I just replaced the whole clutch hydraulic system this weekend on my 87. Top off brake fluid again.