Sunday, May 11, 2008

Going backwards to go forwards

I got another surprise when I tried mounting my calipers on the '73 spindles. They don't fit! None of the calipers I have will fit, including the 320i ones. So I got my depth gauge and micrometer out and took several measurements, comparing the old spindle and rotor (1970-72) with the new one. Fortunately I didn't throw out the spindles that came with the car. And I still had the rotors I bought, with new bearings pressed in them. The newer parts measure 21.6 mm but the older ones 17.0 mm. The calipers fit on the old spindles. The Pelican website says to machine off .125", I calculated 4.6 mm or .181". I spent a few hours visiting machine shops and couldn't find anyone who could do it. After a few hours of this I went over to Part's Heaven. They wouldn't take the rotors and bearings I bought the previous week back and didn't know anyone who could machine the calipers. But the did give me a good price on some 1970 spindles. after painting them and putting in new shocks, it was time to start making some progress.

The car is a 1970 model so I might as well put 1970 parts on it, even if it burns a hole in my wallet. I sold the newer rotors a few days later. So I'm just left with 2 sets of spindles and several brake calipers I don't need. It's a good thing I didn't sell the rotors.

This rotor has been on the car twice now. Once with the 1973 spindle and now with the 1970 one. It doesn't seem to care. The dust shield needed to be convinced that the 320i calipers were the right ones. A bit of banging with a hammer then some grinding and filing did the trick.

I'm missing the clips for locking the pins in place. Anyway the drama is over. I finally have 4 calipers mounted on the car.

I bought some more brake line with the metric fittings. At $5 each it sure is lot easier than making the flares myself. Running the line straight doesn't work for me. Maybe on an airplane they'll do that but all I have to work with is a 12" length of brake line and my hands. If there is any sideways pressure on the fitting it will leak.

I found a 29" long stick to hold the brake pedal down so I can bleed the brake system. With just one bleed valve open I press the brake pedal and then use the stick to keep it down. Then I go and close the bleed valve. Remove the stick and let the pedal return. Open the bleed valve again and repeat until brake fluid comes out. Do this with all the bleed valves. Some rear calipers have 2. The next stage gets the air out. I used a short piece of 1/4" ID tubing taped to the strut so it stays vertical. When I bleed it this way the air stays out. After no more air comes out, I move to the next caliper. When I got done with this the pedal was still soft. I had to loosen the adjustments on the rear calipers and stomp on the brake pedal a few times. That got the rear pads against the disk. After that the pedal was hard if I pumped it a few times - still a bit of air in the system. And it slowly sank to the floor as I pushed down on it - leaks. I tightened up a few fittings but it still leaks; just not as fast. The emergency brake doesn't do anything yet. The brakes are there, just not good enough for driving, whenever I'll get to that stage. So now I've got a roller.

Monday, March 31, 2008

Pressing Bearings

I had a mechanic press the bearings in the early model hubs. The fit was so close I didn't think I would be able to do it. On Friday I went over to Parts Heaven, a Porsche dismantler in Hayward. It really is heaven for anyone restoring old Porsches. I left with a set of rotors and bearings. They were a lot easier to press in than the earlier ones. I used a piece of oak to pound in the inner race and 1¼" wrench socket to drive in the outer ones. After a lot of pounding they were all well seated and my neighbors must have been relieved that it went quickly. The inner bearing and seals go onto the axles, before the rotor goes on. One was a tight fit and had to be driven on with a hammer and a piece of tubing and the other went on easily, but with no looseness.

Another coat of paint on the mud guards and I'll be able to put everything on. I have a set of 320i calipers and ordered some more metric fitting hard brake lines.

Sunday, March 16, 2008

A minor setback

With all the front suspension done, it was time to mount the rotors and calipers. Unfortunately I bought 70-72 rotors and now have 1973 struts on the car, so the calipers don't fit. Anyone need some front rotors for an early 914 complete with bearings? Oh well! On to the rear wheels. I'll fix this later.

I was going to replace the bearings, shocks, and springs. I need to get a 30 mm 3/4" socket first. Or maybe I'll just have a garage do it. There was just one 6 mm screw holding the old rotor on. I wrestled with that big hub nut for a few hours, barely budging it. But I did manage to bend and loosen the small screw holding the old rotor on. The new rotor and caliper went on easily. The worst part of this was cleaning all the caked on grease from the area around the brake line brackets. Now on to the left side.

This is where the 6 mm screw was that was holding the rotor to the hub. I had to drill it out. The easy-out took the head off and this is what I was left with. Just a thin sliver covering the hub threads. Time to put the drills away. I sharpened a small cold chisel and tapped away at any part of the screw that was sticking out; front and back. That got it off the thread and I was able to use an easy-out to remove the remains of the screw; preserving the threads in the hub.

So here it comes! No threads damaged. Drilling into threads destroys drills anyway. Just to be sure, I ran a tap through the holes.

Well that ended well. I'll have to order a few parts from Pelican to finish this, but it was a lot faster doing the rear wheels than the front.

Friday, February 8, 2008

Connecting the anti-sway bar to the struts

My 914 has an after market anti-sway bar and this is what connects it to the strut on one side. The black stuff is a piece of 1/2" thick medium hard polyurethane. It is the same material that the torque tube bushings are made from. No-one had the bushings to replace the tired ones shown here. The other set were in worse shape. They looked like the originals since they had shoulders to isolate the metal parts. This rubbery polyurethane is difficult to work with, but it's what's needed here.

I used a 3/8" Forstner bit but I didn't drill it like this. I clamped the polyurethane between 2 pieces of wood, the top one having a 3/4" hole for drill.

After centering the piece, I clamped the top piece of wood down. The polyurethane is so rubbery it's anyone's guess what can happen if it's not clamped down before drilling. Accuracy here isn't too important. The bushings will be 1.5" in diameter so making 9 of them in this 6" x 6" piece of polyurethane will leave 1/2" of waste between each one.

With all the holes drilled the next step is to scribe the circles. I used a 3/8" rod and one of the washers from the assembly to guide an exacto knife. Nothing will write on this stuff. The only way to mark it is to cut it. But it would have been really tough trying to cut out the bushings with a knife.

I cut them into squares first and made a saw cut on each side to the scribe mark. It took me about 2 Hrs to cut out all 9.

Here's all the bushings and cut pieces of 3/8" ID gas line. The assembly on the right is how it goes together.

And here's the finished product!

Sunday, January 20, 2008

The last few weeks were too cold to work in the garage. In Dec. I put the new bushings on the A arms and mounted them. I learned the hard way that you have to put the torsion rod in first. I found it's easier to slide the bushings part way on the tubes first and then pound everything back with a heavy weight against a wood block. I had to make new rubber seals for the back end of the torsion rods. I still have to make 8 bushings for the sway bar.
The threaded rod for the ball joint I bought didn't fit. Could be because I had 1970 A arms and 1972 struts. Anyway I grinded it down until enough of the threads came out so the lock nut would stay on. Next step is to order some polyurethane so I can make some bushings. That's one end of the anti-sway bar at the bottom right side of the top picture.

In this picture the rubber seal at the end of the torsion bar can be seen. It was cut out of 1/4" silicon rubber.