Friday, July 6, 2012
Front Suspension Overhaul - Day 14
The day started out on a sour note. I had tracked the package from McMaster-Carr containing the socket cap head bolts required to secure the lock housing and had fully expected delivery today when the tracking data said “on truck for delivery”. In fact that was not the case. UPS screwed up and left the package behind at the sorting facility. I asked them to deliver it to make good on their error and of course they refused. It will now be delivered Monday, which means I'll have to wait until next weekend to install the housing.
I began today's work session by bleeding the brakes. I expected a lot of technical challenges here but it turned out much like a routine flush. Running only 5 PSI in the bleeder and watching the level in the reservoir like a hawk I opened the bleeder screw on the right side caliper (farthest away from the reservoir in this case) and saw some spurts of air/fluid before it quickly changed to all fluid. While the old fluid drained into my collection bottle I hit the caliper with a dead blow hammer. I saw one 1/8” size bubble and a couple smaller bubbles exit the bleeder screw into the tubing but not much else. I let it run for a couple minutes and then closed the bleeder screw.
After the fluid appeared in the bleeder line on the left side I saw no additional bubbles for as long as I hit the caliper. When done I anxiously hopped in the car and depressed the brake pedal, which was naturally a little squishy at first given that the pistons hadn't yet expanded to push the pads into the rotors. I pressed the pedal about four times before the brakes firmed up very nicely. Several additional presses resulted in consistent pressure (no pedal sag) so the good news is the vacuum caps I installed on the brake lines appeared to have done their job and the brakes are ready for the test drive.
After cleaning up from the brake bleed I decided to install the new power steering fluid reservoir, secure it to the mount and attach the hoses. Incidentally, I noticed that the new reservoir cap is imprinted with the label "CHF11S only". That's obviously an example of inventory control on the part of BMW as all the new cars share this reservoir and require that $30/quart fluid. I did not receive the “ATF Only” adhesive label that was supposed to be supplied with the reservoir for my application so I decided to clean up the old cap and reuse it for now. I ultimately plan to replace this cap with the magnetized cap Jim donated some time ago. Jim also donated four stainless steel rotor retaining screws sold by ECS Tuning this week. They came too late to be installed but I'll be ready for the next four wheel brake job in about 30K miles...and based on the way I drive that won't be long in calendar time. Thanks again Jim!
I was about to start filling the power steering system while I had the front end in the air and could temporarily attach the steering wheel to cycle the rack but after a search of my parts bins I realized the sealing rings I had on hand were for the differential and vanos oil line rather than the banjo fitting on the power steering pump so I realized I'd have to order those and postpone that work. I went in search of the parts required to install the swaybar and X-brace but found I am apparently short the nuts required to attach the swaybar to the endlink so I'll have to buy those tomorrow. If they don't have them in stock, that work will have to be postponed as well.
I decided to give the tierod adjustment one more look before I snugged down the adjustment nuts. I also used a hammer to knock down the edge of the tierod locking rings and then pulled the boots into their proper locations. I did not secure the boots yet because I plan to use the rack centering tool during the alignment process and that requires access to the area covered by the boots.
Determined to get something of value done today I applied some anti-seize to the face of the rotor hats, installed the wheels without the center caps and then used the floor jack to bring the front end down to the ground for the first time in almost six weeks. The wheel gap is predictably gargantuan (about 1.5” above where it should be) but I expect that to come down after the springs settle. The camber is also noticeably positive but that routinely occurs as a consequence of jacking in general and I expect the wheels to spread out after I move the car just a few feet.
With the wheels firmly on the ground the last job of the day was to torque the axle nuts to the highest torque on the car – 214 ft*lbs. It took a lot longer than usual to wind up my largest torque wrench to achieve that setting but it took only a few moments on either side to hear a reassuring “click”. Due to a lack of clearance (and the risk of damaging the wheels if I slip), I knew I would have to remove the wheels to stake the axle nuts but I decided to leave the car on the ground for now and bask in the glow of a long-awaited milestone.
Tomorrow is expected to hit 100 degrees with high humidity and that's too oppressive for work of any kind so I'm taking the day off. I'll be back in the garage on Sunday to wrap up what I can with the parts on hand.