Answered Joe Blow Max HP track pump, can it be serviced?

[steve_sordy]

This morning, after ten years of faultless performance, my Joe Blow Max HP track pump started binding when pumping. Then it got very stiff as though something was binding inside the barrel, then it suddenly went free but now no longer pumps air. It felt like the end of the valve came off the connector rod. I Googled the problem and got nothing. If only my track pump was a different model to the "Max HP" then it would be easy.

I could not find any service manuals, nothing on You Tube etc. Some promising threads on other bikes sites also proved to be unhelpful.

Surely the Joe Blow Max HP is serviceable? Does anyone out there know how to fix this?

After ten years it doesn't owe me anything, but I am loathe to chuck it in the bin if it can be easily fixed.

 

[#lazy]

Have you looked in the box on the the top shelf in the garage (not that one ) for the manual ?

 

[Jackware]

I know it's out of stock but there's 2 part numbers for your Googlefu training

Topeak Pump Rebuild Kit - Joe Blow Max HP

For JoeBlow Max HP.

www.sjscycles.co.uk

 

[steve_sordy]

I know it's out of stock but there's 2 part numbers for your Googlefu training

Topeak Pump Rebuild Kit - Joe Blow Max HP

For JoeBlow Max HP.

www.sjscycles.co.uk

Yes, I found one very similar to that (in stock too), but before I bought it I wanted to know how to get into the pump. So far, I have failed to find a way, short of destroying the track pump.

 

[steve_sordy]

Have you looked in the box on the the top shelf in the garage (not that one ☺) for the manual ?

No manual came with the pump. The only Topeak (owners of Joe Blow) manual I could find on the internet was a totally useless two-page guide on how to connect the pump head to Presta or Schraeder valves. Normally I can find pretty much anything on the Internet on how to service, dismantle, rebuild whatever I need. Not for the Max HP version. I'm coming around to the view that it was originally a low-cost version and not designed to be maintained. It has lasted me ten years so far though. The £5 one I got from ALDI lasted two weeks!

 

[Jackware]

I can't find any decent images of the top collar on your model but is it like this?

How to disassemble a Topeak JoeBlow Sport II

OK... I searched everywhere, could not find a definitive answer. I've had the pump a few years and use it a lot on several bikes. I like my pump and want it to last as long as possible and I'd ...

bicycles.stackexchange.com

 

[steve_sordy]

I can't find any decent images of the top collar on your model but is it like this?

How to disassemble a Topeak JoeBlow Sport II

OK... I searched everywhere, could not find a definitive answer. I've had the pump a few years and use it a lot on several bikes. I like my pump and want it to last as long as possible and I'd ...

bicycles.stackexchange.com

That looks very promising! On one of the other Joe Blow models, there were screws to remove at the bottom of those holes. No screws in mine, but there may be tabs. I'll have ago tomorrow. Thanks!

 

[Doomanic]

 

[steve_sordy]

@Jackware You have the answer!

For starters it's a two-man job (well my wife and I).

There are two tiny holes at the bottom of the top collar where the lugs are that contain the hose when stored. On some models those holes contain screws that require removal, but no screws on mine, just blind holes.

Using two tiny Allen keys (or other small diameter items), insert into the two tiny holes simultaneously. Then get another person to pull firmly on the top collar. Pressing on the keys pushes two detents out of the way allowing the top collar to be pulled off. In other words, exactly like in your video link.

Once the collar was off, I could withdraw the connector rod and I could see that the O-ring had come off. I cleaned it all up, regreased and reassembled and it works just fine now. But I ordered a service kit anyway, so I should be good for another ten years.

 

[steve_sordy]

Well, the service kit arrived, I got the TRK MAX01 and it's the wrong bloody one!
I needed the TRK MAX02. The difference is the outside diameter of the O ring, the 02 is a larger diameter than that in the 01.
(And yes, I now know that @Jackware pointed me at exactly the one I needed! Double rats!)

Now I've got all the bits and know what thickness of O ring to get I'll have a go at finding an O ring of the correct size. B&Q or Wickes are sure to have some. Rats, what an arse-ache.

 

[steve_sordy]

I bought a load of mixed O rings from B&Q, all stated as 1/8" which is 3.175mm. I measured the new one from the wrong kit at 3.5mm. It is a reasonable assumption that the O ring from the correct kit will also be 3.5mm.

Hmm will standard 1/8" rings fit? Nope, close but no cigar! So, I'm going to have to buy another new kit + P&P, just to get the O ring.

The link so helpfully provided by @Jackware took me to SJS Cycles - out of stock.

I tried half a dozen or so sites, all out of stock until I found a place with one left, they even warned me that it was the last one! When I tried to order it, the site seized up. I rang in and the charming Megan offered to go have a look and get hold of it so that I could order it over the phone on Monday. She rang me back in several minutes to tell me that the stock record was wrong, they too were out of stock! Stock not due in until late next month.

 

[steve_sordy]

The saga continues.

I measured the old O ring and it was 3.3mm thick (not the 3.5m of the wrong kit that I had purchased). i also measured the ID of the Track pump barrel and got 29.24mm. I measured it several times at different positions around the circumference just in case it wasn't perfectly round (it wasn't). Measuring a damaged O ring was a bit more tricky. I held it between the jaws of the vernier calliper and then eased off until it fell out. I repeated that and got 29.24mm, same as the track pump barrel.

So, 29.24mm OD and 3.3mm thick, inferring an ID of 22.64mm. All I had to do now was to find one that met those measurements! The sizes looked really odd to me, but nothing ventured nothing gained.

I found myself on the Simply Bearings website, O ring section.

Choose Nitrile, Viton, EPDM, O-Rings Seals by chemical resistance and temperatur
I chose "Nitrile" O rings.
https://simplybearings.co.uk/shop/S...5/index.html?selection=Nitrile+Rubber+O-Rings

They offer a filter to find the O ring from the ones they have. You can select from cross section, ID, and OD. I started with cross section to find they had 3mm, 3.5mm and 3.53mm. I worked my way through those looking for ID or OD that fitted best.

Long story short I chose 3mm and a 29.5mm OD. I ordered a pack of two and crossed my fingers. It is fractionally large on OD and a bit too big on ID. (29.24 - 6 = 23.24 compared with 22.64).

Anyway, they arrived today and I have just tried one, with a bit of added TF2 grease. It works!! The track pump pumps air, it feels normal in use. Really pleased.

 

[Jackware]

At last!

 

[steve_sordy]

At last!

In total, more than twice the cost of a proper spares kit, but substantially cheaper than a whole new track pump!
And of course, I got that smug rosy glow I get when I fix something myself.

And no more wanking away with that old bike pump!