Saturday, June 30, 2007

Re: More fuel-line work

I reinstalled the fuel-pump, filter, and rubber hose assembly, poured in a half-gallon of gas, reconnected the battery, and tried starting the engine. Turn. Squeek. Turn. Squeek. Smell gasoline.

The plastic fuel line between the fuel pump and the engine is cracked and leaking fuel at 28 psi. The engine would not start.

Thursday, June 28, 2007

Re: Fuel hoses and clamps

Under the right rear of the car, above the heat-exchanger and hot-air supply ducting sits a Bosch fuel pump with three hose attachments (in, out, return). My 1974 Porsche 914 (the last year without a catalytic converter) has Bosch L-Jetronic fuel injection, uses 7mm inner-diameter hose, except for a special two-diameter hose which reduces the fuel supply line from 11mm to 7mm (at the fuel filter).

Because of the unusual OEM part, whoever last replaced the fuel hoses had changed everything around. There was a different tee in the return line, and two hose diameters. One of the return hoses was original, everything was badly deteriorated.

Parts needed: 3 feet 7mm fuel hose ($6/per), one OEM 99918002950 part ($30), 12 clamps ($1.50/per), 1 7mm tee (free), 1 new fuel filter ($36). Rich sold me the "high-quality", swedish-manufactured clamps (which don't pinch the rubber, but are really difficult to fit). Larry gave me the tee for free (Rich wasn't there, don't tell).

Remove the fuel pump first. This was made easier for me, because my car was missing its right-side flexible aluminum duct, which connects the hot-air supply to the exhaust-heat exchanger. Larry suggests finding an appropriately-sized cap (e.g., from a can of brake cleaner or hair spray) and clamp it on. Without this duct engine fumes can enter the cabin, he says.

Time estimate: 4-5 hours.

Wednesday, June 20, 2007

Step 3: Fuel line repair

Yes, I am repairing fuel lines on a future electric car, but this has to be done because the sound recording (step 1) is not yet complete. I needed to repair the rear brakes (step 2) first because driving was unsafe, and now I need to replace some fuel lines because they were "impacted" by the brake work.

Problem: as I was wrenching and prying around with the right-rear brake-line clip, I broke a fuel line. Gasoline is dripping onto the floor from somewhere between the fuel pump and the fuel filter.

This was really not fun. I placed an open gas can underneath the drip and left my garage door partly open to vent overnight. I needed to drain the gas tank before I could replace the fuel lines.

Tools applied: 1 gas mask, 2.5 gallon gas can, something to plug the fuel-supply line (e.g., a 21/64" drill bit) after you've cut the hose, lots of disposable gloves, and another car ready to accept more than 10 gallons of gasoline.

Tuesday, June 19, 2007

Re: Rear Brakes

Task: replace Porsche 914 rear brakes, including rebuilt calipers ($300/per), new pads ($60/set), new stainless-steel flexible brake lines ($90/set), and new rotors ($60/per).

Tools needed: 11mm flare-nut wrench for the brake-line connectors, 19mm open-end wrench for the caliper retaining bolts, 17mm flare-nut wrench for the original flexible-line connectors (my replacements were standard 11/16), 6mm hex wrench for the old caliper plugs, 10mm socket wrench for the new caliper plugs

I paid a little extra to buy parts from HPH in Redwood City so I can drop in and ask questions. The chief mechanic Larry has answers, but when I ask about removing the rear brake lines, "oh, those are the hard ones." True.

Problem: the flexible line is connected to the frame by two clips, which pin the metal/flex connection to the body. The lower clip is fully exposed, but the upper clip is buried underneath the chassis, above the heating duct, motor mount, emergency brake cable, and fuel pump (right) or master brake cylinder (left). Larry's answer, do it with a small vice-grip pliers and/or a screwdriver and/or whatever works. After many attempts, I got it: attach the pliers and rotate the clip about 30 degrees, use the screwdriver to pry it loose. After you get the clip out, pull the metal line down several inches so you can get the wrenches in.

Putting the clips back in is another challenge. Larry's answer was again, "whatever works". He showed me an arm-length pry bar and hammer, "and, put a little grease on the clip so it'll be easier to remove next time". The grease was key, but Larry has a lift and I have jack stands. You really have to get creative here.

I did all this pulling and prying of clips on the right side first, there was an accident before I could continue (*). It takes about as long to replace each brake line as it does to replace each caliper/rotor/pad assembly.

Time estimate: 8-10 hours (without the final "brake bleeding" step)

(*) Watch out for fuel lines (see next post)!