toyota celica clutch

[alyssa]

2000 Toyota Celica GT, manual transmission.

The vehicle is very difficult to shift.

Operation of the clutch pedal is driving the slave cylinder but I am not sure it is moving enough. We tried bleeding the slave cylinder. When the bleed fitting was opened and then closed the clutch pedal stayed on the floor. The pedal was pumped up and down by hand about 10 times. Upon the next attempt to bleed the slave cylinder a great deal of air came out. This process was repeated several times with the same result. During the hand pumping the slave cylinder piston barely moved.
After the vehicle was allowed to sit for an hour or so, operation of the clutch pedal again generated motion of the slave cylinder to about the same extent as we started with.

The next day the slave cylinder seemed to be operating slightly better (had a little more throw) and after the vehicle was started it shifted smoothly into reverse. However, after shifting the vehicle back to neutral and pumping the clutch an attempt to shift into reverse resulted in gear grinding. After getting the transmission into reverse the clutch wanted to re-engage with the clutch pedal fully depressed.

I think I know what the problem is but was looking for a second opinion and some advice before I start tearing into this. It does not look like an easy repair just based on the location of the components.

[tac]

Typically, when you bleed any system (clutch, brakes) you'll need to make sure there is sufficient fluid in the reservoir as you pump out either air or extra fluid.

I believe the Toyotas around that era simply shared their clutch and brake reservoir - which might explain why starting the car built up some presssure (power brakes, back-fed pressure into the clutch line).

For safety's sake, double check the brake fluid reservoir. And then when you try re-bleeding the clutch, make sure you start with the brake fluid reservoir full, and keep an eye on it as you build up pressure in the clutch lines that the brake fluid reservoir doesn't dip too much. When you're all done, double check your brakes as well to make sure no air was introduced into that system either (spongy feel).

Good luck!

[alyssa]

(08-09-2011 05:20 PM)tac Wrote:  Typically, when you bleed any system (clutch, brakes) you'll need to make sure there is sufficient fluid in the reservoir as you pump out either air or extra fluid.

I believe the Toyotas around that era simply shared their clutch and brake reservoir - which might explain why starting the car built up some presssure (power brakes, back-fed pressure into the clutch line).

For safety's sake, double check the brake fluid reservoir. And then when you try re-bleeding the clutch, make sure you start with the brake fluid reservoir full, and keep an eye on it as you build up pressure in the clutch lines that the brake fluid reservoir doesn't dip too much. When you're all done, double check your brakes as well to make sure no air was introduced into that system either (spongy feel).

Good luck!

Thank you Tom.

Before I performed the bleed I did check on line, as I was confused by my inability to find the clutch fluid reservoir, and you are correct. The model combines the brake and clutch reservoir into one component.

The reservoir was full (close to the MAX line) when I started the bleed process and it did not go down appreciably during the bleed attempts. I only got a few ounces out of the bleed fitting. I think the decrease in level of the reservoir can be fully attributed to the amount in the collection container.

I was actually thinking that the source of the problem was the piston seals on the master cylinder, but I was hoping for confirmation before attempting to replace it. My thinking was that the vacuum formed on the slave cylinder side of the master cylinder piston, which forms when the clutch pedal is released and is designed to draw fluid from the reservoir into the master cylinder is actually pulling air through the master cylinder piston seals due to age or degradation.

The master cylinder is up against the firewall tucked into the far corner behind the battery (not a problem) but also blocked by part of the hard metal body panel on the top and the brake/clutch fluid reservoir and brake master cylinder inboard.

On the inside of the car there is a bolt penetrating the firewall with a nut which may be the mount for the master cylinder but this does nothing to alleviate the difficulty of getting to the hydraulic lines to disconnect them from the master cylinder before removing it from the vehicle.

[tac]

Some designs aren't well suited to gravity bleeding and work much better with a pressure bleeder approach. Effectively, you:

Open brake fluid reservoir and use a turkey baster to remove some of the fluid
Press the clutch to the floor
Inject brake fluid into the system via the slave clutch bleeder fitting
Open and close the bleeder between pumps of the pressure bleeder, always checking to be sure you are not overflowing the brake fluid reservoir

It's most definitely a 2-person operation, but can be effective at bleeding a system that is drawing air. It can also clear clogged line with the back pressure.

You may be able to rent/borrow one from Pep Boys or a local Advanced Automotive, or if need be buy one:

http://www.jegs.com/p/Motive-Products/Mo...4AodNCFF1Q

[alyssa]

Tom

Thank you again for your help.

I will try this method.

[tac]

Please let us know how it works out!