Oil Line Questions

[widebody911]

Forget the "Doctor" affectation - from now on, you can call me "Captain" - as in "Hazelwood"

It looked like I had a leak in the oil line that loops across the engine/transmission junction and goes on to the thermostat. It had a steady drip going, and folx at the drag strip were pointing and commenting (and I don't think it was the fact that my pumps didn't match my handbag)

I raised the car and cleaned everything with engine cleaner and hot water, and found a nice, steady leak from that line. I discovered it was rubbing lightly on the head, and that appeard to be where the oil was coming from.

I had a backup line, a braided steel affair of unknown provenance, but it was apparently built for this purpose, as it has the correct metric fittings and dropped right in. However, this line eliminates the rubbin' (as in rubbin' on my 315/35's) and goes directly into the thermostat.
Of course, this new line leaks, too.

I took the hard line to a radiator shop to have them test it, and they say they can't find a leak.

On to the questions;

• What else could be leaking, if it's not the hard line?
• The shop can swage [sp] in new rubber sections on the other oil lines. The hose they have is almost 1/4" thick - is that thick enough?
• Any idea what car this braided line came from? It's not a home-made screw-on fittings jobbie.
• what kind of pressure do these lines experience?

[Chuck Moreland]

1/4" should be fine. Just be sure the material stands up to oil.

The pressure that line sees is very low, probably in the tens of PSI range. The oil flows from there, through the cooler, through the filter and into the tank. Cooler and filter are designed to flow without significant resistance, so no real back pressure. Worst is when the oil is cold.

Even 100 psi would be considered trivial by your hydraulic hose friends.

No idea where the braided hose came from. Sounds custom to me.

Where on the line do you see the leaks? Fittings, middle?

There are several areas that leak commonly right above that hose. The oil pressure sending unit, tstat, and breather all leak oftern.

[Bill Verburg]

The common leaks at the forward end of a 3.6 are the temp/pressure senders and the power steering pump block off. I had what appeared to be a constant mist of oil on the S hose. Turned out to be the power steering pump block off, Dry as a bone since it was resealed.

[widebody911]

Ok, I just spent the entire day trying to get new oil lines. The first place that said they could do it backed out once they saw the size of the lines. They refererred me to another shop, who said they'd done a few 911's but had come-backs (honesty is good); they sent me to another who said "no problem" until I got there and they said "oooh, it's too big!" That's the first time I've ever heard someone say that about my hose!

They referred me to yet another shop, who said they could do it, but they didn't have automotive hose in stock. So I went by the local speed shop, bought some braided line, and had the other shop (Capitol Rubber) cut the fittings off the old lines and put them on the new.

I didn't necessarily need new tank and thermo lines - I was originally going to have them fix the big long special hose I had (!), but I figured "hey, I have 'em off..." Besides, I could not bend the rubber lines at all! They would creak and crack when I tried.

So, it cost $90 for 2 15" sections of -10 braided line (and a remnant - they insted on selling me a full 3') and a 5' section to replace the custom line; then $40 to have the fittings put on while I waited, and they let me watch. (normally it's $4.99 a minute just to listen!)

I woulda been cheaper to go with rubber, but nobody was sure which compound to go with, etc, etc. Braided line was a slam-dunk "yes it works" so I went with it. Extra points for the bling-factor as well!

[widebody911]

Here's the special all-in-one line; goes from the pump all the way to the thermostat. One nice thing about this line is it gives me a little extra room for the wide tires in the back. Maybe that's what it was built for.

[Chuck Moreland]

So did you find the leak?

Are you sure you have -10? -10 is 5/8, and your hard metal lines are 19mm, about 3/4 inch.

[widebody911]

Originally posted by Chuck Moreland
So did you find the leak?

I think so. It's sitting with it's a55 in the air right now running. Dry as a bone so far. This leak was on the left side, the the power steering block-off is out of the picture. Temp sender area is dry; don't remember where the pressure sender is.

Are you sure you have -10? -10 is 5/8, and your hard metal lines are 19mm, about 3/4 inch.
Not sure. I put the fitting to each roll of hose until I found one that fit. I thought it was -10, but I could be wrong. It's one size bigger than what I used on the front oil cooler.