Is my clutch master cylinder bad? - Toyota Nation Forum : Toyota Car and Truck Forums


» Auto Insurance
» Featured Product
Advertisement
Wheel & Tire Center

Go Back   Toyota Nation Forum : Toyota Car and Truck Forums > Toyota Truck, SUV and Van Forums > Hilux (Pickup) Forum > 89-95 Toyota Pickup/Hilux

89-95 Toyota Pickup/Hilux Discussion forum for the 89-95 Toyota Pickup/Hilux owners. NEW!

ToyotaNation.com is the premier Toyota Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 06-27-2013, 03:10 AM   #1 (permalink)
New TN User
 
Join Date: Sep 2012
Location: Costa Mesa
Posts: 32
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
View John999's Photo Gallery
Is my clutch master cylinder bad?

I have a 1992 Toyota pickup, base model, 22RE, manual 5 speed, with 205,000 miles. I suspect that my clutch master cylinder is bad. I have to push very hard on the clutch pedal oftentimes to get the tranny in gear in all gears especially reverse. Sometimes I cannot get the tranny into any gear and have to slam down on the pedal or turn the engine off and play with the shifter to finally get in gear. I removed the carpet from underneath the clutch pedal to to extend the clutch pedal travel and be able the get the truck in gear. The clutch was replaced about 25,000 miles ago. The mechanic bled the clutch system when he replaced the clutch. There is no leakage from either the master or slave clutch cylinders that I can see. The brake fluid level is at the maximum line in the clutch master cylinder reservoir. I have the rod that connects to the clutch pedal and that goes into the master cylinder screwed out as far as it will go. Should I try bleeding the clutch system first or just replace the master and slave cylinders? Many say to replace both cylinders at the same time if one is bad especially for a vehicle this old and with this many miles on it. Thanks for any replies.
John999 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-27-2013, 06:25 AM   #2 (permalink)
YOTA Master
 
Vicoor's Avatar
 
Join Date: Sep 2006
Location: Manassas, VA
Posts: 2,364
Gameroom cash: $200055
Thanks: 0
Thanked 81 Times in 77 Posts
iTrader Score: 0 reviews
View Vicoor's Photo Gallery
The clutch master cylinder can go bad without leaking. It is possible for the fluid to bypass inside the cylinder.

Typically this results in the pedal feeling soft, not hard as you have described.

The clutch pedal rod should not necessarily be adjusted all the way out, has this been adjusted to try to correct this problem?

I would suggest to check the clutch pedal adjustment as per the FSM

If the clutch hydraulics were working correctly it would be unusual for air to have gotten into the system. But not impossible. It would be a good idea to try bleeding the hydraulics, but that is typically only necessary when you have worked on the system.

Problems with the clutch disc, pilot bearing and pressure plate can all results in engagement issues as well. And a problem with the pressure plate can also result in increased effort to depress the clutch pedal.

An experienced technician should be able to give you a good idea how it's working by how it feels, That said, I've worked on cars for over thirty years and only ever worked with a handful of truly capable technicians

Some of the less capable technicians always want to replace all the components because that makes it less likely that they misdiagnose the problem. That said, if all the components are very old and the fluid hasn't been changed with any frequency, it is not bad consideration to change both the cylinders to prevent creating a problem.

I hope this info is helpful

Victor

.
__________________
Don't talk about it, Just do it!


Last edited by Vicoor; 06-27-2013 at 06:31 AM.
Vicoor is offline   Reply With Quote
Old 06-27-2013, 07:13 AM   #3 (permalink)
Cressida nut
 
kamesama980's Avatar
 
Join Date: Jan 2006
Location: Columbus, IN
Posts: 4,104
Gameroom cash: $639795
Thanks: 2
Thanked 271 Times in 258 Posts
Lifetime Supreme Member
Garage
iTrader Score: 0 reviews
View kamesama980's Photo Gallery
+1 all the way out will mess it up. the master doesn't reset to it's starting position to allow fluid back in from the reservoir. can't complain because doing it the wrong way doesn't help.

When the clutch was replaced, was any of the hydraulic system replaced?

Have you checked the pedal bracket? I've seen several cases of the bracket bending on our trucks.
__________________
-Russell
"You don't get to judge me for how I fix what you break"
'94 Pontiac Firebird LT1, T56
'90 Cressida, 7M-GE, M5
'91 Toyota Pickup, 22R-E, M5, 2wd
kamesama980 is offline   Reply With Quote
Old 06-27-2013, 07:32 AM   #4 (permalink)
Soylent Green sales
 
fourwd1's Avatar
 
Join Date: Jul 2006
Location: the Socialist State of Maryland
Posts: 8,211
Gameroom cash: $895255
Thanks: 5
Thanked 476 Times in 455 Posts
Lifetime Supreme Member
iTrader Score: 1 reviews
View fourwd1's Photo Gallery
The clutch pedal breaking where it mounts to the firewall is fairly common, check that.
Also, get underneath and watch the slave cylinder engage the clutch fork while someone is working the pedal.
Make sure you are getting the proper amount of travel.
__________________
SEARCH before asking
84 4Runner rockcrawler - ARBed 5.29's, 36" TSLs, dual t-cases w/ 4.7 crawler gear, Chevys, 30 spline Marlins
83 p/u trail rig - Buick 231 V6, Weiand intake, Holley 4 bbl, TH-350 auto w/700R4 low gearset, dual tanks ...
89 4Runner - stock
http://www.cardomain.com/id/fourwd1
fourwd1 is offline   Reply With Quote
Old 07-05-2013, 05:33 PM   #5 (permalink)
New TN User
 
Join Date: Sep 2012
Location: Costa Mesa
Posts: 32
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
View John999's Photo Gallery
more info

I edited this post to make it easier to read.

The clutch pedal spring is missing. I did not know this until a couple days ago when I was checking the pedal free play. I just picked up a new pedal spring from the dealer. I can see where the spring connects to the pedal but not where the other end of the spring connects to the truck, so I could not attach the spring. How does the pedal come back up without a spring? Does the pressure in the hydraulic system push the pedal back up? Could not having a spring installed for a long time have caused damage to the clutch system?

These are the measurements I took yesterday:the push rod play is 4-5mm. This is the minimal play I could get and only by screwing the push rod out until it was almost disconnected from the nut on the pedal. The pedal free play, which is defined as the push rod play plus the distance the pedal travels until clutch resistance is felt, is about 24mm. The clutch is kind of mushy so my pedal free play measurement may not be very accurate. Maybe it's easier to measure it accurately with the pedal spring installed.

There is no cracking on the bracket that the clutch pedal connects to that I can see. I hear no odd noises like cracking or squeaking when depressing the clutch pedal. My mechanic welded a new piece onto the bracket when he replaced my clutch about 25000 miles ago because there was a lot of cracking on the bracket, and I could hear a cracking noise when depressing the clutch pedal.

No parts of the clutch system have been replaced as far as I know. I bought the truck with 138000 miles on it.

I have a lot of trouble getting the truck into gear sometimes and have to slam down on the pedal or even shut the engine off to get it in gear. Sometimes when I start the engine with it in gear and the clutch pedal fully depressed the truck lunges. But most of the time the shifting operates smoothly.

I fully depressed the clutch pedal down with a bar and checked the lever on the transmission that the clutch slave cylinder rod connects to and could not move the lever. Then I removed the bar and let the clutch pedal all the way up and was able to move the the lever on the tranny back and forth fairly easily but felt the resistance from the slave cylinder. With the clutch pedal fully up or fully down the lever on the tranny was still perpendicular to the tranny and the slave cylinder rod seemed to be fully extended with the pedal up or down, so I did not see any travel for the lever or the push rod.
[/FONT]

Last edited by John999; 07-06-2013 at 04:27 PM. Reason: hard to read
John999 is offline   Reply With Quote
Old 07-05-2013, 07:24 PM   #6 (permalink)
YOTA Master
 
Vicoor's Avatar
 
Join Date: Sep 2006
Location: Manassas, VA
Posts: 2,364
Gameroom cash: $200055
Thanks: 0
Thanked 81 Times in 77 Posts
iTrader Score: 0 reviews
View Vicoor's Photo Gallery
First, when you make a post that long, try to break the text up into smaller bits.

It's really hard on the eyes trying to follow that long.

Not having a spring shouldn't hurt anything but the way it feels.

And yes the hydraulic pressure will push the pedal back up as long as everything is working.

A bypassing master cylinder can be somewhat intermittent. Usually they will be worse when the vehicle is cold/or just starting out. then get better after you work it a bit.

mechanical issues to look for are a bad pilot bearing. Usually these will make a noticeable "whirring" when you depress the clutch and the transmission is in gear.

Also usually when a clutch is very worn it will slip. sometimes depending on several factors the can get worn enough that the grooves in the disc are worn flat. this can make the clutch want to stick to the flywheel or p-plate

If the clutch hub is coming apart it can cause the disc to not run true and drag. this can come and go as well.
__________________
Don't talk about it, Just do it!

Vicoor is offline   Reply With Quote
Old 07-08-2013, 10:55 AM   #7 (permalink)
Cressida nut
 
kamesama980's Avatar
 
Join Date: Jan 2006
Location: Columbus, IN
Posts: 4,104
Gameroom cash: $639795
Thanks: 2
Thanked 271 Times in 258 Posts
Lifetime Supreme Member
Garage
iTrader Score: 0 reviews
View kamesama980's Photo Gallery
Quote:
Originally Posted by John999 View Post
I have a lot of trouble getting the truck into gear sometimes and have to slam down on the pedal or even shut the engine off to get it in gear. Sometimes when I start the engine with it in gear and the clutch pedal fully depressed the truck lunges. But most of the time the shifting operates smoothly.
I see a winning number here. This means the clutch is not fully disengaging.

The lever (actual name is the clutch fork) should move significantly as you press the clutch pedal. don't quote me but I think it's around 1/2"-1" where the slave connects.

Those two pretty well condemn the hydraulic system. If the slave failed, you'd see heavy fluid leakage, you don't which leaves the master. I'd replace the slave and the line as well just to be complete. The rubber on the master failed, the rubber lines and seal on the slave are just as old.
__________________
-Russell
"You don't get to judge me for how I fix what you break"
'94 Pontiac Firebird LT1, T56
'90 Cressida, 7M-GE, M5
'91 Toyota Pickup, 22R-E, M5, 2wd
kamesama980 is offline   Reply With Quote
Old 07-20-2013, 03:24 AM   #8 (permalink)
New TN User
 
Join Date: Sep 2012
Location: Costa Mesa
Posts: 32
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
View John999's Photo Gallery
Fixed the problem

I replaced the clutch master and slave cylinders and the rubber system hose and that solved the problem. The cylinders are Aisin OEM that I got for good prices from Partsgeek, and I bought the hose from the dealer for $33.00. I believe I bled the system really well because at the end I did not see any air bubbles coming out. I bled it by myself by pumping the pedal then holding it down with a rod then opening the bleed screw then closing the screw and letting the pedal back up.

I drove the truck with the floor carpet up with the floor metal exposed after replacing the parts and did not get any grinding in any gears, so I put the carpet back down in place and the shifting seemed to get a little more difficult and the reverse gear grinded a little a couple times. So I'm thinking about cutting out a rectangular section of the carpet so the clutch pedal can travel all the way to the metal floor. I set the pedal free play at around 2mm. I don't think I can get it any smaller. FSM spec for pedal free play is 1-5mm. I have the pedal height set correctly.

The clutch pedal spring was missing so I bought one from the dealer, but I can't see where the spring attaches to the truck. I wriggled around and was able to get my hand way back under the console and felt a small tab with a hole in it in line with the clutch pedal, but there is a plate blocking the way between the pin that the spring attaches to on the pedal and the tab with the hole in it. How necessary is the clutch pedal spring? I assume it has some useful purpose, but the clutch system and pedal seem to be working fine without it.

Last edited by John999; 07-20-2013 at 03:39 AM.
John999 is offline   Reply With Quote
Old 07-22-2013, 07:35 AM   #9 (permalink)
Cressida nut
 
kamesama980's Avatar
 
Join Date: Jan 2006
Location: Columbus, IN
Posts: 4,104
Gameroom cash: $639795
Thanks: 2
Thanked 271 Times in 258 Posts
Lifetime Supreme Member
Garage
iTrader Score: 0 reviews
View kamesama980's Photo Gallery
Reverse will grind no matter what if you go into it too soon after pushing the clutch down. It isn't synchronized, sliding straight cut gears. Either wait a second or 2 longer to shift to reverse or put it in another gear position first.
__________________
-Russell
"You don't get to judge me for how I fix what you break"
'94 Pontiac Firebird LT1, T56
'90 Cressida, 7M-GE, M5
'91 Toyota Pickup, 22R-E, M5, 2wd
kamesama980 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Toyota Nation Forum : Toyota Car and Truck Forums > Toyota Truck, SUV and Van Forums > Hilux (Pickup) Forum > 89-95 Toyota Pickup/Hilux

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 06:30 AM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
ToyotaNation.com is an independent Toyota/Lexus enthusiast website. ToyotaNation.com is not sponsored by or in any way affiliated with Toyota Motor Sales, USA, Inc. The Toyota, Lexus and Scion names and logos are trademarks owned by Toyota Motor Sales, USA, Inc.