New CV boots for Ruby
December 2, 2016
When I switched to winter tires I was surprised to find a substantial deposit of grease inside the right front rim. The boot looked intact, but closer examination revealed a bit of cracking in one location, so axle disassembly seemed inevitable before I took the car on a sanded road.
The local auto parts supplier had access to the boots, but I had to resort to Amazon for a 32mm, 12 point impact socket for the axle bolt. Two days later the set of sockets appeared at the house, courtesy of Canada Post.
There are no videos explaining how to perform this unglamorous repair to a Cayenne. I found one cryptic explanation on RennTech.org by a man named Whippet who popped one in to fill a need. Perhaps I’ll post an addendum to fill in a few gaps where I was left bewildered.
I removed the right front half-shaft successfully in pursuit of the cracked boot. After a thorough bath in the parts washer, there wasn’t any apparent internal damage to the joints, but now I have to figure out how to pop off one end or the other prior to re-lubing both cv’s and adding boots. Major cleanup around the brakes is in order. Fun, but messy.
At the moment I’m stuck until I find instructions on how to disassemble the half-shaft.
I had to search VW sites to gain insight into how the half-shafts come apart. Eventually I ran across a video where a guy separated one with a slide hammer, but he said that a flat board with a slot for the axle would work pretty well for removing the outer joint if you hit it sharply with a hammer, only his board broke. Mine didn’t until the part which goes through the brake rotor had come apart.
I’m beginning to believe that the trick to working on a Porsche is to use a heavy enough hammer. A light mallet had no effect on the axle, but a 20 ounce construction hammer’s effect was smooth and incremental. (Similarly, I have found an eight-pound sledge perfect for the disassembly of ball joints and wheel removal.)
The cleaning of the CV joints involved hosing down each in its turn in a stream of varsol over the parts washer. Not bad at all, though I’ll need to buy more solvent.
Then came the battle-of-the-day with after-market clamps which came for the boots. The two which fasten the narrow ends to the axle were perilously large for the job, but might work. The others were too small. After a long battle I managed to fit the outboard clamp (no other type of clamp will work in this position because of narrow clearances). The clamp next to the front differential was 1/4″ short, so after almost two hours of trying, I twisted on a 4″ plumbing clamp. There’s no shortage of clearance in there. I read somewhere that the pipe clamp’s a stronger alternative to the ubiquitous zip-tie on DIY boot-repair projects.
A hint I read online eventually allowed the breakthrough on the outboard boot: a contributor recommended drilling a small hole 1/4″ ahead of the other holes on the boot clamp. He said this allows the use of needle-nose pliers to pull the clamp together enough for it to latch when other attempts are unsuccessful.
Surely enough, with the extra hole I was able to snug up the clamp enough that it would hold its place so that I could use the specialized crimping pliers purchased for the purpose. I guess it’s hard to visualize the benefit of drilling a hole in a pipe clamp, but smooth pieces of stainless steel offer very little to hang onto, especially when one attempts to install them over a neoprene enclosure bursting with grease.
My day with the quarter-shaft was quite challenging. What vexes me more than anything is that I spent a day trying to salvage one of the only inexpensive parts on this car: rebuilt quarter shafts are very cheap on the gray market. On the other hand, my labour is free.
Monday, 5 December, 2016 5:54 a.m.
The axle went back into the car yesterday. Everything went surprisingly well until it came time to torque the six studs to the differential. I couldn’t keep the axle from turning, so I pressed Bet into service on the brake pedal. After I wore out both her legs pumping the dead pedal, we concluded that the brakes wouldn’t hold sufficiently for me to put 60 lbs of torque onto the studs, so brake bleeding moved up in the schedule.
Careful not to damage the brake line or electronic feed from the ABS, I had removed and stored the calliper early in the process. This left the line dripping brake fluid into a tray for two days. Now I can’t get the brakes to bleed, I assume because there’s an air lock in the system.
Charlie told me at various times he had dealt with dry brake lines on his 968 during an extensive rebuild, and it took a while to get the fluid to flow. His old bleeding pump applied pressure at Ruby’s fluid reservoir*, but to no effect. I’m nervous about online reports of broken pump lines spraying paint-destroying brake fluid all over everywhere, so I’ve been very tentative in my use of this unknown tool.
Ruby’s paint is still almost perfect.
Resetting of the two alignment-critical bolts and torquing of suspension and axle parts remains incomplete.
If anybody has any ideas on reviving brake fluid flow, please chip in.
*Number 1 rule: Make SURE you’re pouring the brake fluid into the correct reservoir.
3:30 p.m., Monday, 5 December
Brakes now work. Under a concealment panel I found the actual brake reservoir. No amount of positive air pressure on the power steering reservoir would bleed the brakes. So I siphoned nearly 1/2 litre of Motul DOT 4 brake fluid out of it. Then I refilled the reservoir with hydraulic oil (like it said on the reservoir, only for the Kubota). Shall drain and refill the power steering system asap. The unlabelled plastic tank was nearly empty when I opened it, expecting a brake reservoir, so I looked no further.
Bleeding the brakes was straightforward once I had located the right reservoir and put some brake fluid in it. To its credit, the car’s sensors quit complaining as soon as the brakes worked. Ruby didn’t hold my mistake against me.
When I told Bet she asked, “Are you going to tell Charlie?”
Now all I have to do is torque everything. The brake calipers are already at about 200 lb. The torque wrench clicked at 140. Then I added a 2’pipe to an old ratchet and tightened them up one lurch. The axle nut goes to 340, but I’ll use my tractor wrench with a 4′ cheater pipe and take it easy: for my rotary mower blades it calls for 540 foot pounds torque. Immediately after it’s tightened, the nut is too hot to touch.
I’ll have Bet hold the brake for the six axle screws which torque to 60 pounds. And so on. I’ll look up the suspension numbers. Then off for alignment again.