I have a zefal HP pump which the internal pump diaphram thingy is disintegrated. A search only shows replacements for the pump head. is there a way to fix the internal plunger diaphragm?

Did you look really hard? This was 2 clicks from a search for "zefal pump parts": Pumps - ZEFAL

How old is the pump? The only time I have seen pump "washers" go bad was if they were leather and never kept up or synthetic and the wrong lube was used. Andy

The pump was on a 1970's vintage Austro Daimler. Not my bike, well, it's my bike as of yesterday. Don't know how long it was on there but I suspect a long long time. I asked Zefal what size washer I need. The website doesn't say and since it is disintegrated I can't measure it.

I'm glad you posted this since I picked up 2 Zefal HP pumps recently. They pump air really well but the piece that fits over the valve stem is worn pretty badly.

Are there no US parts distributors? I've never ordered directly from overseas before.

Jicafold I'll see if I can get a measurement for you in a few minutes.

I got a measurement of 18 mm on both of the rubber pieces at the largest part of the skirt. I tried to measure the inside of the pump tube but my calipers wouldn't quite reach far enough in.

Pump head rebuild kit and piston rubber diaphragm here. https://store.biketouringnews.com/bicycle-pumps/ As mentioned a search may also turn up some other sources such as ebay etc.

https://store.biketouringnews.com/ze...nt-pump-black/
You may just have to replace the whole pump.
pay the $40 bucks, Boom.. Done !




...

Thanks Crankycrank I hadn't seen that store before. I have them bookmarked now though.

18mm is correct. I bought this part last year for my HP, and it fits perfectly: https://www.ebay.com/p/Zefal-HP-Vint...d=273277149521. I'd have bought from the Zefal website, but I wanted to avoid shipment from Europe and euro-dollar conversion.

Thank you Philbob57. That was the information I was looking for. Rather than the unhelpful 2 cents offered by dsbrantjr or people that can't seem to repair their own stuff like fietsbob.

I have 30 year old silca impero on a couple bikes, and a blackburn frame fit that has gone on 2 international tours ,
(Zefal supplies the minipump on Bromptons)

mostly I use my floor pump at home ..

I dont fix things from pictures over the internet, doing your web searches for you .

they have to physically be in front of me ..

Zefal is sending me a washer for free. Boom...done!

I know that the new Zefal pumps are almost the same as the new ones, but is nice to have a same vintage looking pump on the bike.

Why spend $25 or more when you can spend $10 or even less, especially if you're not quite sure which HPX to buy? Why buy an HPX pump if you think the HP looks better? Why get a mini-pimp when the HP will probably get to higher pressure more easily?