Hy-Flo air pump overhaul

[Jon Evans]

Hi,

I've purchased a vintage Medcalf Bros. Hy-Flo pump off eBay and I plan
to strip it down completely and overhaul it.

I've extracted the two pistons, they are about 12mm diameter and not
'butted' - it's a 12mm wide piston all the way. The bottom of the
piston seems to be soldered over although it is solid at the top where
the hole for the crank is drilled through. I'll probably have a go at
removing / replacing the solder with a blowtorch.

There's a 3mm hole in the side of the piston for an oilway which seems
to connect up to the crank bearing hole. Inside I can feel with a thin
screwdriver that the piston wall at the side is maybe only 1.5mm thick.
It's full of cack which seems to be blocking it up.

My question is, do you think this cack is just old hardened oil, or
would it originally have been something which maybe helps the oil to
whick up between the cylinder and the crank? If the latter, I'll have
to replace it with something after I've cleaned it.

Also any tips on solvents or techniques to use to strip hard baked on
oil would be appreciated.

It's a beautifully made old thing and I'm looking forward to getting it
looking and running good again.

Jon

[mark]

This post might be inappropriate. Click to display it.

[e***@gmail.com]

Hi Mark,

Post by mark
Nitromors paint stripper works well on all that burnt on crap
Even does a decoke without the nead for wire brushes.
Just a toothbrush used here.
http://img.photobucket.com/albums/v190/aboard_epsilon/rover%20420/carbonoose.jpg
http://img.photobucket.com/albums/v190/aboard_epsilon/rover%20420/combucham.jpg

Great pictures. I'll give that a try, I think I've got some Nitromors
in the shed somewhere.

Thanks

Jon

[Taffhamster]

To Jon Evans (or anyone else who might be able to help!)

I was wondering how much joy you've had restoring your Hy Flo. I as
because I recently acquired one which needs a bit of an overhaul. I
needs cleaning and oiling, but the biggest problem is that it doesn'
seem to be pumping out much air. My main motivation for buying it wa
silent aeration of my fish tank, but the fact it's such a beautifu
item of kit is a bonus!

Having no knowledge in these areas, I'm looking for someone who migh
have a idea how to sort out this problem (or at least let me know it'
a hopeless case).

Any advice would be appreciated.

Thanks

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[e***@gmail.com]

Hi,

Post by Taffhamster
To Jon Evans (or anyone else who might be able to help!)
I was wondering how much joy you've had restoring your Hy Flo. I ask
because I recently acquired one which needs a bit of an overhaul. It
needs cleaning and oiling, but the biggest problem is that it doesn't
seem to be pumping out much air. My main motivation for buying it was
silent aeration of my fish tank, but the fact it's such a beautiful
item of kit is a bonus!

Job done, I completely stripped it down and rebuilt it. I've put some
photos online here:

http://flickr.com/photos/jonevans/sets/72157594368490524/

I still don't use it however - it's not as quiet as one is lead to
believe, and it also runs quite hot. I'd be interested in finding out
if that's normal.

Jon

[dazzer_up_nort]

i am in uk and have found a very good web link for these pumps. the
really are quiet when running, and simply awesome to watch.

http://www.sonik-systems.com/pumps/

they do run very hot, thats normal, there is a link on the page for th
original instructions sheet.

i do hope this thread can be relived because i am also rebuilding th
pump i have here and would be very interested in the rebuild of th
actual pumps.

thank

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[David Littlewood]

i am in uk and have found a very good web link for these pumps. they
really are quiet when running, and simply awesome to watch.
http://www.sonik-systems.com/pumps/
they do run very hot, thats normal, there is a link on the page for the
original instructions sheet.
i do hope this thread can be relived because i am also rebuilding the
pump i have here and would be very interested in the rebuild of the
actual pumps.
thanks

Always very suspicious when a site describes its wares as "collectors'
items" and does not give prices.

David

[dazzer_up_nort]

cnt disagree about the "special" nature of the site, but its got th
instructions for free. and should you need them, spare
avaialable......

didnt actually say go and spend all your money did i??

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[sparky537]

Hi all been doing a bit of tidying in the loft and came across my Hy fl
model C.
I actualy had to order it made by metcalf bros and it cost a fortun
£200+
back in 1987, its had realativly little use and I can confirm that the
do run hot due to the type of motor ( it works the same as an electri
meter inducing eddy currents in the disk ) so draws the same curren
even if stalled.
As you have all seen they are a marvel to watch, I first fell in lov
with them at school back in the stone age.
they had several in the science labs running various things.
Now I have unearthed it I feel that a good clean and check is i
order.
Thanks for this thread as I now know where to seek parts.

Cheers, Mar

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[Mark Rand]

Post by sparky537
Thanks for this thread as I now know where to seek parts.
Cheers, Mark

Which thread would that be then?

More of rcgroups nonsense?


Mark Rand
RTFM

[Mark Rand]

Post by Mark Rand
Which thread would that be then?
More of rcgroups nonsense?

Oops.Just a rather old thread :-(

PS, they are relaxing in an over-heated sort of way...


Mark Rand
RTFM

[leatherworker]

Hi guys
I have two of the Hy-flo air pumps. One is a single piston type and th
other I have just bought is the double piston type. I am currentl
overhauling the double piston pump and using spirit based brak
degreaser to clean out the pistons. I'd advise using caution whe
cleaning the pistons as when you have fluid inside them and you move th
piston rod, you will get a face full of the fluid shot at you, hehe.
found this out as I was working, doh
As another member has said, I am aiming to remove the upper pisto
cylinder seal to replace it as the hole has worn larger and is leakin
air

--
leatherworke

[Mark Rand]

On Thu, 24 Dec 2009 16:24:52 -0600, leatherworker

Hi guys.

It doesn't help to resurrect a three year old thread that, itself, was
resurrected nearly two years ago.

Start a new one If you expect people to know what you are talking about.


Mark Rand
RTFM

[leatherworker]

Just tried de-soldering the piston, DON'T.
I found out that the piston itself although made of brass, is coate
in some kind of plastic layer to reduce friction and therefore melt
when you try to desolder the seals on the cylinder. There is also a sea
surrounding the piston rod as it passes though the upper part of th
cylinder.
This of course means I have trashed one of the pumps, great!I will tr
to get another set of pistons somewhere, maybe Metcalfs

--
leatherworke

[Briggsy67]

Hi would you be willing to sell the electrical parts on your knackered pump … I have one that had been submerged in water for a number of years … I’ve got the mechanical side running beautifully but no power at all to the moto