Hypermax turbo failures - Diesel Forum

jaybee · 05-25-2005, 01:48 PM

Last week I made a trip of about 1500 miles towing. This is the first long distance towing I've done since last June, and it turned up a few issues. The last time I towed in June I developed an exhaust leak where the Hypermax header pipes slip into the turbo mount. I also managed to bend the tip of a single vane on the compressor wheel, but have yet to figure out how that happened with an intact air cleaner system. I fixed all these problems after that trip.

On this trip the turbo developed a pretty good exhaust leak about 200 miles into the trip as I left Knoxville on 75 north. My peak boost dropped from 13psi to about 9psi and I still had plenty of power, but EGT's were a good bit higher. Looking under the hood you could see the soot building up on the firewall right behind the turbo connections. We continued on to our destination in Portland, Indianna with the leak getting noisier all the way.

When I finally got a chance to work on the truck and pull the primary pipes I was surprised to find the passenger's side pipe was stress cracked about 90% of the way around the tube where they expand it to mate up to the Ford manifold. My short term repair was to have it welded by a welding shop not far from where we were and stick it all back together. It ran great for the return trip.

When I got the Hypermax kit I was rather disappointed with the primary pipes. They are actually designed to fail if you ask me. They use a fairly small diameter tube to keep gas velocities up, and then have to expand it a good bit to mate to the manifold. They start with rather thin walled (looks like 16ga) mild steel tubing, so once it gets expanded it draws VERY thin. The other problem with the pass side is the shape of the bent tube. I makes a large U shaped bend with overly long legs. Since the mounting is only at the ends of the legs the middle tends to vibrate like a tuning fork (like a diesel really vibrates much???) and eventually it's going to give at the weakest spot like mine did. I really wish they'd have used a bit heavier wall tubing, or gone with stainless. The other option would be a two piece welded design so the smaller tube wouldn't have to be expanded so much.

I plan on adding a tab to my pass side primary and the downpipe so they can be bolted together. This would keep the primary from vibrating so much. The driver's side doesn't appear to suffer from the same issue due to its shape.

I still really like the Hypermax systemn as a whole - I just wish the primaries were a little better thought out.

Has anyone else had this pipe fail?

Jason

Huff · 05-26-2005, 05:02 AM

I had the drivers side start leaking, turns out the small 1/4" SS cap screw had fallen out allowing the pipe to move out of the turbo base. If that happens and is not corrected, the pipe will develop work hardening cracks near the exhaust manifold. (like an injection line without it's dampeners) Check the small 1/4" screws that hold the pipes into the turbo base. They need to be snug or they may fall out. Mine fell out in about 1 year. Going on it's third (maybe 4th, can't remember) year now without any problems.

I think I put a split ring type lock washer on them.

The pipes are made that way to keep them equal length. If they were made from stainless, the expansion from heat, would be enough to cause stress cracks.
Keep that little cap screw in and you won't have any problems.

aceohearts · 05-27-2005, 12:55 AM

How did the downpipe slip out of the turbo housing, and how did you correct it? I just installed a used Hypermax on mine, and the downpipe once it was bolted to the bracket doesn't seat properly in the housing. I figured if I had to, I could rig up a bracket for it, but if there is an easier way to fix it I'm all ears...

Huff · 05-27-2005, 06:47 AM

He had one of the primary pipes slip out. The down pipe can be considered in place if you can't see the iron sealing ring. If you see the ring, the little tab on the downpipe may have gotten tweaked, however you may be able to losen the two bolts on the tab, have a helper then shove the downpipe as far as possible into the turbine outlet, then tighten the tab screws (back of the cylinder head).

jaybee · 05-27-2005, 07:43 AM

Actually, I have not had the primary pipes slip out. They are seated in place and the 1/4 - 20 bolts securely fastened, yet I get some leakage past the joints. I never had a problem with them leaking the first 20,000 miles after I installed it. But, then I did the 6 speed swap and had the entire system off. I had an awfull times getted the primaries out due to carbon buildup and rusting, but they weren't damaged in the process. Ever since I put it back together they have both leaked some.