Pesky leak - Turbo banjo nut washer

[IDAHO-POWDER-PUSHER]

I tracked down a pesky coolant leak on my 2017 Sidewinder mtx. I thought it was the coolant hose leading to the turbo, but all the clamps were tight. So I tore it down to see what was going on. I found it was leaking out the top banjo nut washer on the turbo. I was only losing a cup or so of coolant every ride ( 50 miles or so). I never found the correct washer, but found one very close. I guess our turbos are also shared with subarus (sti's , not sure what years though. ) I used 4 new washers from the subaru dealer, part number 803912040 . The subaru dealer said they always see this leak in their shop. I got them installed, and also upgraded the coolant hoses to and from the turbo with a high temperature silicone coolant line from my local industrial hose company. I bled the system, and so far no leaks. Hopefully this helps.

 

[Turboflash]

One common thing I've seen that causes leaks on many sleds is the factory clamps aren't sized right. Some are too big for the size hose they go on. If you look at the far right pic, you'll see it. When I do engine work, I put much better clamps (aircraft liner clamps) that are sized correctly so when they're tightened they end up round and don't have a flat spot under the worm drive area. That's what happens when they use a clamp that's too big. The flat spots aren't round so they can leak even if the clamp is tight. Another ugly piece of Cat DNA.

 

[Turboflash]

One common thing I've seen that causes leaks on many sleds is the factory clamps aren't sized right. Some are too big for the size hose they go on. If you look at the far right pic, you'll see it. When I do engine work, I put much better clamps (aircraft liner clamps) that are sized correctly so when they're tightened they end up round and don't have a flat spot under the worm drive area. That's what happens when they use a clamp that's too big. The flat spots aren't round so they can leak even if the clamp is tight. Another ugly piece of Cat DNA.

Just FYI - posting link to liner clamps. Notice the liner prevents the hose from touching the threads of the clamp. Much smoother clamping action and if sized right, stay very round as they are tightened.

Breeze Liner Clamps | Aircraft Spruce

Breeze Liner Clamps An integral extension of the band as an inner liner protects soft-surface hose (silicone and others) from damage caused by extrusion or shearing through the band slots. Liner clamps afford maximum protection to soft hose

www.aircraftspruce.com

 

[IDAHO-POWDER-PUSHER]

Just FYI - posting link to liner clamps. Notice the liner prevents the hose from touching the threads of the clamp. Much smoother clamping action and if sized right, stay very round as they are tightened.

Breeze Liner Clamps | Aircraft Spruce

Breeze Liner Clamps An integral extension of the band as an inner liner protects soft-surface hose (silicone and others) from damage caused by extrusion or shearing through the band slots. Liner clamps afford maximum protection to soft hose

www.aircraftspruce.com

Very nice. I will have to get some of them. The clamps I used did chew up the outer jacket of the hose.

One thing I did notice on mine also, is that the lower hose to the turbo seemed like it had too large of an inner diameter. It slid on and off the tube without any resistance, even with both ends. It didn't appear to have been stretched out to much on the ends, but it seemed very sloppy to me.

The top outlet fit a 3/8 hose, but the lower was a bit larger, maybe like 7/16 ( metric of some sort I'm sure) . I guess 7/16 isn't a common size for hoses, but the new 3/8 stretched perfectly over it and fit well. It fit much better than the original hose on it that seemed oversized for the connection.

 

[blevis213]

Just FYI - posting link to liner clamps. Notice the liner prevents the hose from touching the threads of the clamp. Much smoother clamping action and if sized right, stay very round as they are tightened.

Breeze Liner Clamps | Aircraft Spruce

Breeze Liner Clamps An integral extension of the band as an inner liner protects soft-surface hose (silicone and others) from damage caused by extrusion or shearing through the band slots. Liner clamps afford maximum protection to soft hose

www.aircraftspruce.com

What size are needed 7/16?

 

[Turboflash]

I bought a whole range of these clamps to replace most of the junk used at the factory. Each one has a useable range. Just measure the OD of the hose you want to clamp and order a size that will clamp a little smaller than that and you should be covered.