strut rebuild

General discussion forum for J30 and M30 owners!
rwhite
Posts: 40
Joined: Tue Dec 11, 2012 4:36 am
Car: 1996 J30

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I'll put the warning up first that there is no guarantee this will work. I've had success about 50% of the time when I have done this on motorcycles. So far I've been going 2 weeks on the j30 strut rebuild and have no leaks yet.
What you need is a strut compressor, suitable shock oil and a pint of hydraulic jack stop leak. I always use aw32 hydraulic oil for shocks. It's about 10 weight equivalent. Depending on your climate you can go up to 20 weight shock oil (available at any motorcycle shop). If you get dedicated fork oil be prepared to pay. Transmission oil will also work but it's about 7.5 weight. If you use transmission oil I would use transmission stop leak so you can be assured it will mix properly as I don't know if the jack oil will mix right. Before you get started put the car on Jack stands, pull the wheels and clean all the dust, gravel and dirt from the strut and wheel well. You want it clean so you don't get dirt and other junk falling on your clean shock.

1. There are plenty of threads on strut removal so I won't go into depth on that. But if you remove everything from the strut assembly but the lower ball joint you can pull it out of the fender well. That means unbolt the brake lines,abs line from the strut, pop the tie rod end, one end of the link and unbolt the tension rod from the control arm.

2. You'll need a strut compressor to get the springs off. Once tension is off the springs you can pull the strut mount off the top. I always use a impact for this so I don't have to worry about trying to hold the rod while getting the bolt loose.

3. Once the spring is off the strut use a pipe wrench or other suitable tool to remove the big gland nut off the top of the strut. Use a dental pick to get the o-ring off the top of the cartridge. It's important that you remove the o-ring before you pull the cartridge so that you don't run it past the threads and cut it up.

4. Use a soft toothbrush and soap and water to clean the gland packing and the o-ring. Pour enough of the stop leak in a bowl to cover the gland packing and o-ring and let sit while you clean up the other parts.

5. Pump the cartridge until you have all the old oil out. Then use a siphon pump or something similar to get the rest of the oil out of the housing. I honestly just used a long piece of vacuum line and sucked it out. Don't suck to hard or you'll have a mouth full of oil.

6. Tape a rag to the end of a wooden dowel and soak in mineral spirits and use like a mop to clean the inside of the housing.

7. Now to put the oil back in the shock. How much you ask? I don't have a clue. The datsun and z guys use any where from 265-285 ml on setups similar to ours but I could find nothing definitive on the j30. I used 265 ml and it seemed to work ok.

8. Put 150ml of oil in a cup and place the end of the cartridge in it. Pull the piston up and down until it gets hard and oil is coming out the top bleeder holes. That way you have all the air out. It should take most of the 150ml.

9. Pour 50ml of stop leak and 65ml of oil into the housing.

10. Place the cartridge in the housing, put the o-ring in and install the gland nut.

NOTE: if you have threads exposed on the the gland nut you don't have the cartridge seated fully. Remove the nut and fiddle with the cartridge until it is seated fully. A little tricky but it can be done.

11. Tighten the gland nut.

A new shock boot is the best option but even if the old one is ripped up it needs to go back on. The upper part of the boot is hard and that is the bump stop on these cars

12. This is where it becomes a pain and a helper is nice. Because these are not air charged the piston wants to suck down. You have to pull the piston out and try and get the spring, cap and strut mount on without it sucking back in. You'll need 6 hands and will look like a monkey humping a football but it can be done. I was able to do it by myself. FYI: the cut out on the spring cap goes toward the outside of the fender well.



Once all that is back together just jack the strut into place and do the other side. Like I said you have a 50/50 chance of this working and not leaking. I'm sure if I had the time and a donor gland nut I could find a suitable oil seal that could replace the gland seal.


rwhite
Posts: 40
Joined: Tue Dec 11, 2012 4:36 am
Car: 1996 J30

Post

You can get the jack oil and stop leak at oriellys or autozone. It's just regular hydraulic oil but you can get it in a quart size for $4 or so.


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