xlrogue

A couple of weeks ago I started having problems with my Park floor pump--on my long stem valves it would leak like crazy and on short stems the pump head would pop right off the valve when I got up around 100 PSI. Since I'm fond of having plenty of air in my tires and I needed to ride the next morning, on a whim I got out the O ring assortment I got from Harbor Freight and put the smallest size ring (inside diameter about half the diameter of the valve shaft) on the valve shaft, seated on the indentation. Voila! The pump seals better than it ever has. I was under the impression that I was losing 10-15 PSI overnight. Turns out I was losing it connecting and disconnecting the pump. (D'oh!!!) Got my first post revelation flat today and my frame pump also worked better than ever. Maybe this is common knowledge and I'm the last guy in the universe to get the memo, but just in case...

Dubbayoo

I used a Silca track pump at a shop this weekend.....GREATEST.....PUMP......EVER.

G_Sup

aka: Silca Super Pista?

biker7

With respect, there isn't a single thing I agree with that you wrote.
First, a Park pump in good condition works perfectly...what I use. The valve heads are as good as it gets for a modestly priced pump. They have great support if you ever need replacement parts which will keep them operating properly for decades. Second, there is no need for another o-ring or whatever you did either external on the valve or internal to the nozzle. Third...there is no such thing as a tire losing pressure when inserting or removing a pump nozzle. When removing the nozzle, the hiss you hear is the air captured in the hose and nozzle. The tire volume is sealed via the stem valve when removing the nozzle. Lastly, all tires lose air over time as there is no such thing as a perfect seal.
There is no need for extra or different o-rings. Park pumps will last for years with virtually no maintenance.
HTH,
George

Grasschopper

Silca Pista or Super Pista are both wonderful as is the Specialized Air Tool and Air Tool Pro. They are all rebuildable as well.

I have a Pista and an Air Tool Pro (was having issues with my Pista which was being rebuilt but I needed a pump while I waited so...) and wouldn't reade them for anything else.

botto 

Air Tool Pro FTW.

El Diablo Rojo

Thats what I have (Super Pista) and I totally agree.

WheresWaldo

I have a Pista that I just rebuilt, but I need to find a different chuck. maybe that is what I should look for today. Agreed that it is the best pump ever.

urbanknight

+1 well worth the money. I know people still using theirs from 20 years ago while my plastic pos lasted 3.

ElJamoquio

I haven't tried a presta valve pump that I've liked yet, even at the LBS. I use the presta-> schrader conversion.

xlrogue

No quibbles with Park support--they are amazingly responsive. I have to disagree with your assertion that there is no such thing as pressure loss when the nozzle is inserted or removed--that's what I thought until my O ring adventure. The pressure gauge on the Park would show a 10-15 PSI loss every day until I put the O rings on the valve stem--now there's maybe a pound or two diff--not enough to really even show on the gauge. This morning I checked the tire I changed on the road yesterday and found to my surprise that it was at 130 PSI, when usually with frame pumps it's tough to get much over 100. Additionally, there's no hiss of escaping air upon insertion or removal. I've used a lot of pumps in my time so I'm pretty sure it's not lack of experience. To each his own--I'm keeping the rings, but I promise not to force anyone else to use them.

Wil Davis

All other things being equal, biker7 is partly right… …however, I've found that occasionally (like on both tubes on one of my road-bikes at the moment) I will be faced with a valve which has to be set up just right, else none of my pumps (Park Tools PFP-2, zéfal hp, zéfal hp X3, X4, Topeak Road Morph, all in perfect condition, BTW ) will seal properly.

xlrogue's idea is an excellent solution, and as I happened to be in Home-Boy Despot today, I picked up a $1.39 bubble-pack of Danco #60 "O" rings (part #96744); perfect solution! Thanks for the tip, xlrogue!

- Wil

BTW the "O" rings also will help prevent loss of the retaining nuts if you've dispensed with using the valve-caps.

charlisity

Then how can you tell? Tire squeezing with calibrated fingers?

xlrogue

No, I bite them gently with my calibrated jaw....

Actually, the gauge looks like maybe it went down a pound or two, but it's so close I can't say with any certainty. And after all the pro Silca testimony, I may just have to get one the next time I get irresistable bike stuff consumer urges.

biker7

Bingo. The only way to determine pressure on any gauge be it separate or integrated with the pump is to break the seal of the valve in the stem of the tube. Whenever this is done, there is going to be pressure loss. My personal view is this is a moot discussion. Not only is air a perfect gas and therefore subject to pressure loss due to colder temperature but air molecules will permeate a rubber tube over time contributing to pressure loss. The best practice is and always has been filling your tires every time you ride. Extra o-rings are frivilous with no value added.
George

xlrogue

As I noted earlier, one of the benefits I've noticed from adding the O-rings is that almost no air escapes when applying or removing the pump head. Of course, I'm a big fan of frivolity, so there you go. As far as value added, I'll bet resale value of my bike has gone up by at least $.01 thanks to my bold innovative contribution to cycling as a whole, and since by posting repeatedly I've put in $.06($.02X3), I'm way ahead! But, like they say, YMMV. Disclaimer: None of the content of this or any of my other posts should be taken as an endorsement of unsupervised, uninformed, or unintentional use of O-rings. They are a dangerous and expensive technology that should only be applied under carefully controlled laboratory conditions by trained professionals, or humanely treated lab animals.

cyclezealot

Is not an important part of keeping a pump working well, clean them up and grease the diaphram. With what. Silicone grease? The package on my pumps has not one sentence regarding pump maintenance.

StanSeven

It sounds like your pump head isn't on the value stem sufficiently for short stems and may be pressing against the side of the value with long stems, thus allowing air to come out because the value isn't closed.

marnan

My vote is for the cheap plastic pumps. They work and are easy to use. I had an old school Pista back in the 90s and while it was well contructed with steel, brass, and a hardwood handle, I would cut myself on the spokes getting the chuck off the stem, the guage was small and never worked right, and the parts to re-build would cost as much as a buying an entire new plastic pump. This is one situation where new school beats old school.