How to replace oil cooler lines

[SobeLotus]

I became a LH Oil Cooler Line victim today. The oil was all over the road and everyone was looking. No oil light came on so I am assuming the engine still had oil in it. Worst of all, I just did and oil change and the oil dumped had less than 5 miles on it. I have confidence I turned it off on time. Plus, I have faith in synthetic Motul oil.

I am considering changing the line instead of just cutting and crimping because I don't know how much slack is in the line. Has anyone changed this left hand (Drive Side) line? How can I get it through the sill? Does removing the bottom panels help out at all? Thanks for any help.

Attached is the picture of the small hole I found on the line. I hope this was the failure point and not somewhere else. Such a small hole and lots of oil.

[SobeLotus]

Originally Posted by scottross

On my car, there was a plastic clip holding this hose located in the space behind the rocker panel, toward the front. The rocker panel cannot be removed (glued on) so the only way to access this clip was to cut an access hole in the rocker panel. If you remove the body panel the book calls the hinge cover (where the side marker light is located), you see that this panel overlaps a portion of the rocker panel. I cut hole with a hole saw in an area where this panel will cover it, allowing access to the clip, which could then be removed. At that point, the line could be pulled free, although it still took some effort. I attached a wire to the old line before pulling, so that a new line could be pulled through.

Scottross, I tug on the line and it appears to be stuck. I am assuming it is because there is a clip where you of had yours. How big was the hole you made and exactly where on the rocker panel. (middle, low, etc). How hard did you have to tug to then get the line out?

Is this the way the dealer might perform the same line swap?

Any help would greatly help. Anyone?

[Apex_in_sno]

Having pulled the AC lines out of passenger side, the way that I got to them was via removing the door sill cover, which gives you access to the rear wheel arch area where the Oil line passes through.

[SobeLotus]

Can two oil cooler lines be connect by a coupling? In other words, can two oil cooler hoses by connected to each other?

I have disconnected the oil cooler line at both ends. When i try to pull it through, it is very difficult and I don't really want to pull hard in case the line breaks inside the sill. I am about to give up and am running out of options.

I am considering ordering a new oil cooler line, cutting the length I need and connecting it too the existing oil cooler line. I hope I am explaining right?

( )======== | ================== ( )
new oil line | old good oil line
connection

If not I can take a picture to explain. Help Help Help.

[evilfij]

My improvised clamp did not hold and it happened again. Hopefully I did not toast another motor.

Anyone have any idea if I can just ditch all the oil cooler lines?

Also, I have the clam off and the new line has 90 as opposed to 45 degree ends and does not seem to fit right. The parts person swears that the part is right and an updated part.

[ChrisH]

Originally Posted by evilfij

My improvised clamp did not hold and it happened again.
....

What kind of clamp were you using? (Screw hose clamp, Oetiker, something home-made, ...? Picture?)

[mOlson]

Originally Posted by ChrisH

What kind of clamp were you using? (Screw hose clamp, Oetiker, something home-made, ...? Picture?)

screw hose clamp

http://www.lotustalk.com/forums/1440752-post13.html

[evilfij]

Three screw on hose clamps.

[TimMullen]

Originally Posted by SobeLotus

Can two oil cooler lines be connect by a coupling? In other words, can two oil cooler hoses by connected to each other?

Yes (in fact, that's exactly what the factory does on the cars with only one oil cooler).

I have no idea if you could pull the fittings through what ever obstructions there might be in the side sills, but I suspect that you can pull the hose with a fitting on the end through the sides, so you should be able to pull the other hose with them coupled together.

Anyone changed hoses with the fittings on the ends? Do the factory replacement hoses come with the fittings already installed?

[ChrisH]

Does anyone know the following (or can measure if you have the pieces lying around):

1) What is the inner diameter of the stock oil cooler hose? (Outer diameter would also be nice to know, although is easy enough to measure on my own car.)

2) On the stock connectors, after removing the crimp and the hose, what is the diameter of the tube over which the hose fits. I would like to know the primary tube diameter, as well as the diameter at the bulge near the tip.

[apexdc]

subscribed

[HiroY]

Originally Posted by evilfij

Three screw on hose clamps.

I wonder if the screw clamp is the culprit of the failure in your case? (I also wonder if the fixed clamp from the factory is also the culprit of the failures to begin with in the cases where the hose slipped right out of the fitting)

After doing all my research on this matter, I theorized that the fixed clamping may be a factor in causing the failures since the fixed clamps don't allow for expansion/contraction of the hose at the fitting with heating/cooling cycles. The Oetiker clamps in contrast allow for this expansion/contraction to take place, thereby preserving the clamping effectiveness over time. Oetiker clamps are used in the Lotus Sport Water/Oil cooler kit that I ended up installing to replace the stock oil cooling setup.

Here is a quote about the Oetiker clamps I had found in my research:

Oetiker clamps maintain clamping force due to their ability to expand as a hose assembly is subjected to temperature cycling. Standard worm-drive clamps can't expand and, therefore, force the hose material to extrude away from the clamp area during a heat cycle. After several heat cycles, they can lose most of their clamping force.

[ChrisH]

One concern I have with screw type or Oetiker hose clamps as compared to stock is that on the stock connector, the outer crimped shell is attached to the connecter, and the shell grabbing on to the outer part of the hose helps to keep the hose from sliding off (if properly crimped), along with the bulge (or flare, or whatever it is called) at the end of the connector's tube. However, with a hose clamp, the only thing keeping the hose from sliding off is the bulge. So, how big is the bulge compared to the primary diameter of the tube, and will the hose eventually compress enough that it slips off even with an Oetiker clamp? (I just bought some to fix a leaky connector, but haven't installed it yet.) I am concerned that our stock connectors may have a relatively small bulge. I am looking for evidence that the connecter should be replaced at least with a barbed fitting (with an Oetiker clamp as well).

Now, if I only knew the inner diameter of our stock hoses so I knew what size of connector to buy.

[evilfij]

I don't know. It seems like an odd theory about expansion and contraction as the clamps were tight and it held for 10k. I ordered the replacement hose, but it was not the same as the original and since the screw clamps had been holding the shop left it with my makeshift repair. I had the pull the clam again and try to fit the hose (which has 90 degree ends with swivels, not 45 degree as was on the car) and it fit but would rub so I called the place I bought the hose and they are looking into it.

It really ticks me off because it can't be that hard to keep oil in a hose.

The theory I am working on is that there is a sticking valve or thermostat or something that cause a pressure surge which causes the weak point to fail.

OTOH, my other love, Land Rover Defenders, have an issue where the oil cooler lines are too close to the exhaust manifold and when they fail over time it ends up causing engine fires. There was a poll and nearly everyone with original lines had a failure and it was 50%/50% on whether there was a fire.

I just hope the engine is ok this time. While the used engine was not that much money the first go around, it was NOT a fun job to put it in and I really don't want to pay a shop this time, but given my work schedule, I probably will have to if I want to drive it this summer.

[SobeLotus]

I believe my old post can answer most of your questions. I also still have the old fitting with a piece of the original hose still attached. I can get any measurements you need. Please read my step by step post.


Step by Step Oil Cooler Line Full Repair



I just checked the replacement last week after I installed the Ultradiscs ORO Edition, and the hose replacement has never leaked. It was a perfect replacement.

[TimMullen]

Originally Posted by evilfij

I don't know. It seems like an odd theory about expansion and contraction as the clamps were tight and it held for 10k.

Ever had a radiator hose start leaking after a year or two? The rubber of the hose gets compressed when things get hot and after a while, it "takes a set". Then the clamp is no longer tight and thing start leaking. That's why screw type radiator hose clamps are not used by the factory (in most cases - Lotus uses them, at least in the front of the Elise) and instead they use the "spring" clamps that you have to squeeze the ends of with pliers to remove them. The spring clamps provide constant force even as the rubber compresses under them.

Same happens with an oil line.

Originally Posted by SobeLotus

I believe my old post can answer most of your questions. I also still have the old fitting with a piece of the original hose still attached. I can get any measurements you need. Please read my step by step post.

Can you measure the inside diameter of the hose (not the part that slips over the fitting - the part a few inches away from the fitting), and the outside diameter of the hose barb on the fittings. That information will be helpful for others looking for the proper replacement fittings.

[ChrisH]

Originally Posted by SobeLotus

I believe my old post can answer most of your questions. I also still have the old fitting with a piece of the original hose still attached. I can get any measurements you need. Please read my step by step post.


Step by Step Oil Cooler Line Full Repair
...

I read your thread multiple times since you first posted it (and thank you for writing it up). The difference is that my oil hoses look to be in good shape (at least where I could see them), and I would like to keep the old hoses. I want to avoid the work of running new hoses up the sides of the car.

I would prefer to just replace the clamps with Oetikers, or if necessary, replace the connectors with barb connectors (also with clamps). I need to get a better understanding of the existing connector dimensions so I can make a judgement on if they really do need to be replaced with barbs. And, if I do need to replace with barbs, I need to know the stock hose inner dimension in order to get the right size connector, and the outer dimension to make sure I have the right size clamp. The stock hose dimensions may not be the same as the new hose you installed.

[tesprit]

Originally Posted by TimMullen

Ever had a radiator hose start leaking after a year or two? The rubber of the hose gets compressed when things get hot and after a while, it "takes a set". Then the clamp is no longer tight and thing start leaking. That's why screw type radiator hose clamps are not used by the factory (in most cases - Lotus uses them, at least in the front of the Elise) and instead they use the "spring" clamps that you have to squeeze the ends of with pliers to remove them. The spring clamps provide constant force even as the rubber compresses under them.

Same happens with an oil line.

+1

This is why you rarely if ever see screw type clamps used on pressurized hose systems in aircraft. The connection will eventually fail and blown engines do not power aircraft well.

The difficulty with repairing these failed hose fittings is that they are BSP and not standard, easily available hose fittings otherwise you could just convert them to Aeroquip style fittings and be done with it. The more you look into this unfortunate situation with these hoses and fittings the more it seems that the best method would be to replace everything in the oil cooling system with coolers that have standard fittings and standard hoses. Of course the downside to all this is the expense of purchasing all these parts and then all the work involved removing the old lines and coolers and replacing them - not an easy or pleasant task by any means. If only they would stop using BSP fittings on British cars........

[TimMullen]

Originally Posted by tesprit

If only they would stop using BSP fittings on British cars........

Actually they use them on Japanese cars too ( or at least used to). Compare the specifications for the Japanese standard and the British standards - last time I checked they were the same...

[tesprit]

OK, let me amend my comment:

If only they would stop using BSP fittings on Japanese and British cars......

No matter if the Japanese use them or not, the fittings are still not readily available to us here in the States........