Great write up man. I am getting the soft pedal thing so if the fluid change dont work, Im all over this. Thanx a ton.

 

Good writeup and pix. Is the new master, a Nissan cyl. or aftermarket from Rockauto? They make them easy to get to don't they?

 

if you bleed it and it still gets spongy its definitely the master cyl. na nissan oem. Hook up $50 its cost $123. They made changes to the upper neck assembly on the new ones. The old one was a piece glued or pressed on. The new one has a once piece molded top. I am guessing thats where the air was coming in at over time. Its really easy if you take off the FakeSTB. Took me 30 min.

 

good write up... really helpfull... looks pretty easy too....good job

 

Nice job. If you leave those pics up for a long time, I'll add it the FAQ Forum.

 

good post, did you do this because of the clutch issues with the altimas? (i'm assuming you did)

how does it feel now?

 

nice i may have to do this myself soon soft pedal FTL

 

I just had the fluid changed today in the master and slave clutch cylinders. It cost 1hr labor and was refilled with the dot 4 oil. It cost about 130.00 total.
Sounds like the master cylinder costs less than that.

I'll post the notes from the sinking clutch problem so if this does become a sticky it is also included.
Great write-up on replacing this part that effects most manual transmission Altima's.
Nice job 1trucavalier.

Notes for sinking clutch.
Clutch sinking to the Floor When Hot
Defective Master or Slave Cylinder or just replace Fluid with a quality DOT 4 or DOT 5.1 Fluid

The clutch works on a totally separate hydraulic system just like the brakes do. The clutch hydraulics actually just take brake fluid. It comes prefilled with Nissan's crappiest possible DOT 3 fluid, and may also come with your choice of contaminants from the factory It looks as if the DOT 4 brake/clutch fluid did the trick for my clutch. But there are still some people that will have defective cylinders (master or slave or both), and the new fluid will not solve the problem on its own without having the cylinders replaced.

Yes, you should completely flush out your clutch hydraulic system and replace the old fluid with a high quality DOT 4 or DOT 5.1 brake fluid.

(DO NOT use DOT 5, only DOT 4 or DOT 5.1 - the DOT 5 is not compatible with any automotive brake or clutch system - it's silicone based)

If you don't know how to do this yourself, I can give you a write up if you are mechanically inclined. It's not a hard job, but it is time consuming and you do have to get right into the very tight space in the engine compartment to constantly loosen and tighten the bleeder valve until the job is done. You will also need a helper that will not get bored sitting in the car pumping the clutch pedal for a few hours

Otherwise, any competent brake shop can flush out the clutch hydraulics for you. I'd bring my own fluid to them though. Again, a high quality DOT 4 or DOT 5.1... The brake shop will just use whatever DOT 3 they have lying around. Also, you probably need to point out the fact that this car has 2 bleeders for the clutch system (the 3.5 does anyway)... One at the slave cylinder on the tranny housing (visible right where the tranny connects to the side of the engine) and one directly beneath the clutch fluid reservoir (which requires removal of the reservoir to get at with a socket wrench).

Many companies make DOT 4 / DOT 5.1 fluids. You will probably have to go to a performance shop to buy them though. Most normal auto parts stores just have the regular DOT 3 fluid. Amsoil, Castrol, ATE, Motul, etc. all make good DOT 4 / DOT 5.1 brake fluids.

Remember, you don't want to get stuck without enough fluid. My clutch used just over 12 oz to bleed correctly to my liking. Make sure you have enough BRAND NEW fluid in sealed containers. Also, another point to keep in mind... Don't buy too much, because once you open a brake fluid container, you MUST use it up within a week. DO NOT store any brake fluid in opened containers. It is extremely hydroscopic and will absorb moisture from the air like mad, in turn making it just as useless as the stuff you removed from your clutch or brake system. You should only keep fluid in sealed containers, or better yet, return unused stuff to the store.
Nice to hear that your fluid flush restored your pedal.
It sounds like the MT clutch mechanism is very susceptible to absorbing moisture. Sounds like the reservoir cap seal is not designed correctly.

In terms of clutch performance, I wouldn't say that the flush made the clutch superior to when my car was brand new, but it certainly did make a big improvement from where it was prior to the flush. I can't even begin to explain how bad the clutch feel was getting, even prior to this loss of pressure incident. My clutch felt like it was always a split second behind my foot (i.e. - too slow). And the grabbing was so abrupt, that I actually had to modify my driving style to make the shifts smooth (didn't notice my adaptation until I went to drive my brother's Vibe... lol). But now, it's great. Very linear, nice solid feel throughout the travel, and the clutch no longer lags behind my foot. The friction point is very stable now (doesn't move around anymore), and the grab is nice and linear, but still quick (which I prefer anyway).

As for the DOT 3 / DOT 4 issue, Amsoil has officially changed the recommendation from DOT 3 to DOT 4 for all Altima's and Maxima's. I guess the V6 engine bay temps can get high enough to boil old contaminated fluid, and the DOT 4 is a precautionary measure to allow the fluid to last longer and prevent this sinking pedal from happening at temperature extremes. Water in the brake fluid also makes the clutch feel very nasty and slow during cold weather spells as well (like the -40 F that we sometimes get in the winter!) But otherwise, there is no functional difference between the DOT 3 and 4 (and 5.1), other than the fact that the latter two can take higher temps than the DOT 3. Nissan should have simply filled these cars with DOT 4 and none of these issues would have occured.

The vacuum bleeder can't be used because it will not fully remove air from the slave cylinder bore. You must have the slave cylinder extended using the clutch pedal to ensure that all air gets pushed out. You can use a vacuum bleeder to change the fluid if you wish, but the final bleeding should always be done the old fashion way to prevent air entrapment. Also, don't forget to bleed the air column after the slave cylinder is fully bled.

...and yes, that slave bleeder is a real a$$ to get at!!! My hands are big, and they don't like fitting in that small space very well. I had a lot of battle scars after this job all over my hand and forearm.
Wherever you take it, just make sure they do it manually without the use of a pressure bleeder, and also make them aware of the fact that this car requires bleeding in two locations, first the slave cylinder, and second, the air column (right beneath the clutch fluid reservoir). Bringing your own fluid would be a good idea to ensure they use high quality stuff.

called my dealer to ask what they would charge to refill the clutch fluid using the bleeding procedure. Guy said about 1 hr labor + fluid.

The bleeder on the slave cylinder is an 8mm. Use a 1/4 in drive socket with a swivel and then a very long extention to get your ratchet above the engine.
The mechanic suggested that the fluid may have lost viscosity due to heat soak. Makes sense considering it only happens after idling in 100+ degree weather and on track days. So i will be putting in some superblue dot4 performance fluid about $16 a liter.
You can thank il signore97 from Toronto, Canada for this excellent write up.

 

i will not take the pics down they will stay in my photobucket folder so you can sticky no problem. I changed mine because I just put in a new clutch and flywheel insert last weekend and for some reason my pedal started to get spongy. I actually when i replaced the clutch this time did not disconnect the hydraulics lines i just pulled the 2 slave cyl bolts, took a hanger and hooked it to the side out of the way and the master cyl still failed POS (nissan replaced that master cyl under warranty in 2006 when i had 60k)!! I also noticed they didnt put 2 of the 10mm screws back and also they didnt put any of my plastic cowl screws back. How do i know? No one has ever touched this car but me and the dealer so I know it was them. I didnt want to take a chance so I just replaced it. Its very rare the slave cylinder goes bad (in our vehicles) but its only $40-45 at the nissan dealer so I replaced mine last year just for peace of mind. I still have the original in my in the trunk along with MAF, TB, etc... I dont throw away anything on this car you never know

 

Do you have the extended warranty?

 

i have 103,000 on her now warranty was up at 89,000. Dealer will never touch this car ever! There is nothing on my car i cannot fix myself so i am good .