Silca Pump Head Problem

petulance said:

Hi all,

I have done some Googling but couldn't find any direct answers so I'm
hoping I can get some here.

I have a yellow Silca track pump (not sure which model, but it has a
plastic handle instead of a wooden one). I used to be able to inflate my
road bike tyres up to 100psi before the pump head would disengage itself
from the valve.

However, I am now lucky to even get to 50psi before the pump head
disengages itself. This was after I mucked around with the pump head to
get it to inflate a Schraeder tube. The pump has been switched back to
inflate Presta tubes but something feels very wrong. I have to use one
hand to hold the pump head onto the valve if I want to inflate the tyres
to 70 - 80psi.

You may have damaged the presta seal - it's a rubber gasket and is a
replaceable part - your LBS shuold have spares. Checkl that you
haven't loosened the top of the brass fitting that holds it in too.

Quoted message said:

An inspection of the rubber hose near the pump head shows a small gap
between the hose and the pump head. This gap does not cover the whole
circumference of the pump head. I'm not sure if the gap existed before
but I had to screw the pump head onto a Schraeder valve and I *may* have
caused the hose to disengage slightly from the pump head.

Any ideas on why I can only get 50psi before the pump head disengages
itself?

It's leaking. You can remove the head

Quoted message said:

Thanks.

went thru smialr scenario 6mths ago

Tightened wire-thing holding hose onto brass head.

replaced rubber grommet-thing inside head (from other pump as LBS/Silca only sell head as complete thing apparently and too ex'y to bother...)

also checking 'lid' of brass head to ensure it's tight too

hopefully they do the trick

also ensuring you have plenty of valve head to actually get pump-head onto

Bleve said:

petulance said:

However, I am now lucky to even get to 50psi before the pump head
disengages itself. This was after I mucked around with the pump head to
get it to inflate a Schraeder tube. The pump has been switched back to
inflate Presta tubes but something feels very wrong. I have to use one
hand to hold the pump head onto the valve if I want to inflate the tyres
to 70 - 80psi.

You may have damaged the presta seal - it's a rubber gasket and is a
replaceable part - your LBS shuold have spares. Checkl that you
haven't loosened the top of the brass fitting that holds it in too.

Thanks. Hmmm, I probably picked the worst public holiday to have damaged
the pump head. I doubt any of the bike shops in my area will be open today.

Thanks. I tried looking online for instructions (and pictures!) but
couldn't find anything.

Replies inline.

flyingdutch said:

went thru smialr scenario 6mths ago

Tightened wire-thing holding hose onto brass head.

I tried to do that, but the wire loop seems permanently attached
to the rubber hose (the pump is at least 6 years old)

Quoted message said:

replaced rubber grommet-thing inside head (from other pump as LBS/Silca
only sell head as complete thing apparently and too ex'y to bother...)

Is this the black washer like rubber piece or is it the Schraeder/Presta
converter?

Quoted message said:

also checking 'lid' of brass head to ensure it's tight too

Done.

Quoted message said:

hopefully they do the trick

also ensuring you have plenty of valve head to actually get pump-head
onto

No problems there, I use 48 and 52 mm valve stems on my tubes.

Try wrapping a piece of white plumber's tape around each tube valve just
under the the moveable part of the presta valave where the pump grips might
just take up enough to compensate for a worn pump head.

Steve
Ideal

petulance said:

Thanks. I tried looking online for instructions (and pictures!) but
couldn't find anything.

Replies inline.

flyingdutch said:

went thru smialr scenario 6mths ago

Tightened wire-thing holding hose onto brass head.

I tried to do that, but the wire loop seems permanently attached
to the rubber hose (the pump is at least 6 years old)

You can cut the old one off, and then use a small hoseclamp to clamp it
back on.

Bleve said:

You can cut the old one off, and then use a small hoseclamp to clamp it
back on.

or get some pliers and twist that sucka till its as tight as, well, a very tight thing!
worked on mine...

Bleve said:

petulance said:

Thanks. I tried looking online for instructions (and pictures!) but
couldn't find anything.

Replies inline.

flyingdutch said:

went thru smialr scenario 6mths ago

Tightened wire-thing holding hose onto brass head.

I tried to do that, but the wire loop seems permanently attached
to the rubber hose (the pump is at least 6 years old)

You can cut the old one off, and then use a small hoseclamp to clamp it
back on.

I took the pump to a bike store in the CBD this morning (Sydney
residents can take a guess ... there are only 2 in the CBD!).

Turns out it was a faulty washer (is that the name for the black rubber
thing inside?). $3 and a new washer later, I tried it on one of the
bikes in the store and the pump seems to work better than before. I'll
confirm this when I try to get to 100psi on my bike later today.

I took the pump to the only bike shop that was open yesterday and I was
stunned by the response of one of the employees (mind you, this was
only a bike hire shop and not a serious roadie one).

"It is usually better to just get a new pump when the old one dies
out."

Ouch! Whatever happened to maintenance and repairability?

Thanks to all who replied.