himespau 

Hi all, don't know if here is the best place, but I figured that fellow vintage enthusiasts would be the most likely to have rebuilt silca pumps. I have a couple of silca pumps, one with the single foot holder and one with the triangular base that can have two feet. I've replaced the leather washer a couple times (once on each pump) and the gauge on one and the check valve on one (also put longer hoses and new chucks on both), so I like the rebuilability of them. I've run into a problem that I haven't seen before and am looking for help.

On the pump that only has one foot brace, a couple months back I had an issue crop up where suddenly it just loses all resistance and lets air go by on the downstroke. I figured, whoops, the leather washer has gone out, so I bought a new one and just used the other pump until I had time to repair the broken one (finally got to it today). I pulled the plunger and was about to unscrew the nut to take the old leather washer off, but it looked like it was still in good condition. Then I noticed that the white plastic piece above it (that the spring contacts) was broken.

That's where I've run into a problem. I can easily find the leather washer, and can get the rubber gaskets for the chucks, the check valves, a new gauge, and even the nuts and washers that whole the leather washer in place, but I can't seem to find that plastic piece.

Does anyone know if/where I can find another one of those plastic pieces? Or something that I can use in its place?

Thanks.

merziac

Are we talking about the leather backstop or the very top piece that goes in the top of the tube?

Pic's?

If the former, never been to this place and don't know if it can be sourced but if plain and flat, I would find suitable scrap, metal or plastic and fab one myself.

Hobbiano 

Is it this piece? https://www.benscycle.com/silca-no--...iABEgKHxPD_BwE

You may want to call them to confirm it fits your pump. I think there were two diameters for these pumps, 28mm and 30mm, at least for the leather piece.

himespau 

Sorry, I should have immediately known to include a picture. It's pretty crappy, but that white piece above the leather that the spring contacts is shown here with a crack. I might have thought it was supposed to have an opening, but there appear to be broken pieces of it inside loose.

The symptom is I had good pressure on the downstroke until about halfway and then loose all resistance as air seems to be getting by the leather washer. No obvious deformations of the barrel.

himespau 

Yes, that's it exactly. Thanks so much. I've never seen that for sale before.

Hobbiano 

See my edit to my post.

himespau 

Good call. I just saw that there was 1 left couldn't find it for sale anywhere else and bought it quickly without thinking about that before someone else did. Don't see a diameter on the listing. Hopefully it's the right one. If not, I'm out 15 bucks, which is a decent gamble vs having to replace the pump.

merziac

No worries, if that piece is just a backstop, I would still be inclined to fab one before I replaced the pump.

I see now it has vents through it, still pretty sure you could make one out of nylon/plastic barstock, surely would take some finesse and whether you could make it work may be a whole different story. The upside would be this pump not becoming a parts donor and building a new skillset that would pay off from here on when you could save other things from becoming useless.

P!N20

My pump has a plastic washer above the leather gasket which broke a few months back:



Found a stainless steel washer more or less the same dimensions and it’s working great.

WaveyGravey

Off the subject, but I recently gave up on my Lezyne pump and purchased a Silca based on the recommendation of my LBS. The Lezyne was to big of a PITA to use.

Hopefully I have better results with the single foot holder and press on chuck. Just beginning to use it everyday.

himespau 

I have a cheap nashbar pump (with lezyne chuck), that I leave in my garage for the schrader valves on the kids's bikes (and ball needle). I had an issue with the lezyne chuck that it really wanted to pull out the valve core of presta valves that had a removeable core, but I really like the bleeder valve button on those chucks. I usually keep the superpista (I think - it's the one with triangular base that stands up on its own anyway) with the Silca hiro clamp-on chuck (I put an old lezyne chuck in-line for the bleeder button that those come with) in the garage as well for my and my wife's bikes with presta valves.

My (currently nonworking) silca pista, I keep in the basement near my trainer. That one has the push-on chuck. I go back and forth with whether I want to replace the push-on with the clamping style like a another hiro. The push-on style is really fast and convenient when it works, but sometimes the push-on chuck pops off. The clamping style chuck is nice when you're blowing up from flat because it can securely grab onto the valve of an empty inner tube when there is only a little bit of the valve sticking through. I went through a batch of tubes that, even fully extended, only barely stuck through the rim, and was having the devil of a time keeping the push-on chuck attached to them. On the other hand, sometimes the lever on the clamp-on style really gets hard to use because spokes get in the way.

SJX426 

The push on can be adjusted by loosening or tightening the cap that keeps the washer in place. If air leaks past it you can tighten it down to reduce the ID of the hole. The other option is to buy a replacement.

KLiNCK

The nylon plunger plate will last for many years. The reason that they eventually fail is from repeatedly slamming the plunger into the base of the bottom of the plunger stroke.
Adjust your plunger strokes so that you aren't "bottoming out" and the plunger plate lasts much, much longer.

himespau 

Good to know. Trying to go fast and get the most air out of every stroke is not the best strategy. Noted.

himespau 

Thank you for this. The part arrived today, it was the perfect fit and my pump was working like new again. Just need to learn to stop bouncing on the bottom of the downstroke during my pumping motion. Other people mentioned just buying a metal washer (the plastic piece is both washer and nut, so I'd need a nut too). I think I bought a replacement washer/nut set that is supposed to go below the leather washer. If this breaks again, I'll just put that spare set above the leather washer since the threading and diameter should be correct. Though, if I retrain myself about pumping, hopefully it'll last a long time.