MyRedTrek

Bontrager Turbocharger HP pump has developed a leak that can be felt escaping around the pressure gauge sight glass. Any insights as to what broke and the viability of repairing it?

Thanks!

P.S. I gained a new appreciation for the design of this Bontrager pump when I went to my spare Walmart pump that I have on hand for just such an occasion. It's got a fatter cylinder and moves more air initially but that last 20 psi or so is much more of a chore. I will say the pressure gauge on the Walmart pump is surprisingly accurate as tested against my digital pressure gauge.

alcjphil

Pumps with larger diameter barrels are designed for tires that don't need higher pressure. The larger barrel moves more air per stroke but requires much greater effort as tire pressure increases. Narrower barrels move less air per stroke but require less effort as pressure increases. It is barrel diameter that determines how hard it is to pump a tire to high pressure

grumpus

Inside the pressure gauge is a curved metal tube that distorts as pressure increases to deflect the needle - it's likely there's a crack in this that's allowing air to escape.
​​​​​​Pressure gauges have a standard pipe thread, so it should be easy to find a cheap replacement with similar pressure range once you've determined the thread size. Note that the American NPT pipe threads are different than the British BSP threads that most of the rest of the world uses, stuff sourced online may not state which system it uses just e.g. 1/8 inch or 1/4 inch (which also doesn't correspond to the external thread dimension).

HillRider

I believe Bontrager has a "lifetime" warranty on those pumps. Any Trek/Bontrager dealer should be able to replace it at no cost. I also have a Bontrager pump and the dealer told me if anything ever breaks bring it back for a free replacement.

MyRedTrek

No lifetime nuthin' and turns out Bontrager or whoever actually makes their pumps stopped making this particular pump several years ago. I'll see what else the Trek store has and at some point look inside this ailing pressure gauge and see if I can fabricate something to get it fixed.

HillRider

Take it with you to the Trek store and see what they will do about the warranty. You may get a newer model as a replacement. Replacement pressure gauges are available from Industrial Supply houses like Grainger and McMaster Carr but a lot of bike pumps have the gauge molded in, not threaded, so replacement isn't practical.

MyRedTrek

Did the dealer tell you you had to have the receipt? I bought this pump when it was David's World Cycle a chain which has since gone over to Trek Bicycle. I don't know if they keep purchases in a database though I know they put my info into a system when I bought it.

I'm not finding anything about a lifetime warranty on Bontrager pumps. The only lifetime warranty I find is on the frame, fork and carbon wheels.

I'll see what they say at the Trek store.

MyRedTrek

No lifetime warranty but they gave me $20 off on a Bontrager dual pressure pump that looks like a superior pump. He also showed me a pic of the internals of the Turbocharger gauge - it's likely an O-ring that's gone bad - if so I'm sure a replacement will be readily available and will have it as a backup. Got some other things while I was there - tires, lube, bottom bracket cartridge bearing replacement, tubes.

soyabean

The OP let their pump freeze in the garage over the winter.

Moisture/water gets into the "curved metal tube", that's what froze and expanded.

When working at a LBS, I have explained this to clients why I denied them a warranty exchange.

MyRedTrek

Lol - the pump stays in the house but where I am there's no chance of it freezing in the garage,

Btw that gauge looks nothing like the internals he showed me a picture of after looking up the Turbocharger HP - what he showed me was a plastic unit of some sort that uses an o-ring - I can't swear to it being the correct piece. I'll have to see what it looks like whenever I get it apart.