Rednal compressor problem?

[Peter1450]

Hi Newbie here......... always used this site as a source of information but have decided to register as I have acquired a mig welder and compressor for my garage and have a few teething problems I would like some advice on please.
Compressor is a Rednal with a 3 hp single phase motor belt driven to a three cylinder air pump ,the performance seems a little disappointing for a compressor of this size, two of the cylinders of the pump get fairly hot whilst the third stays cool,is there likely to be a problem with this and is there any way of testing the compression before stripping down to inspect?
Thanks in advance Pete

 

[rtbcomp]

Welcome to the forum.

If it has 3 distinct cylinder and head assemblies you should be able to disconnect the outlet pipes and fit a pressure gauge.

Does it have separate inlet ports? You may be able to feel the air being sucked in, compare all 3 cylinders.

 

[normspanners]

Welcome.
Some of the rednal compressors have two feed pumps supplying the high pressure cyl, if it has two air filters take off the filters, as rtb says, and see if both are sucking, the heads with the filters should both be same ie equal temp, the high pressure one should be hotter, also check all the interconnecting pipes supplying the high pressure head and tank they could be leaking. The cyl that is cool will be the suspected one, sounds to me as if you have a reed/ valve down, air being compressed, always gets hot.

 

[Peter1450]

Thanks for the quick response chaps...........sorry for being dump , but where would I find the reed / valves and what am I looking for? There are three cylinders all with air filters, none of the connecting pipework appears to be leaking. Looks like I may be able to to get a compression tester onto the heads, would I be looking for any particular psi or just all within the same range? Thanks again.

 

[brightspark]

Thanks for the quick response chaps...........sorry for being dump , but where would I find the reed / valves and what am I looking for? There are three cylinders all with air filters, none of the connecting pipework appears to be leaking. Looks like I may be able to to get a compression tester onto the heads, would I be looking for any particular psi or just all within the same range? Thanks again.

expect each one to pump over the required running pressure and not below

 

[eil]

Take the cyl head off the cylinder that's running cool sounds like a problem with the suction valve/reed.

 

[the snooper]

but where would I find the reed / valves and what am I looking for?

the reed valves are between the cylinder and cylinder head sometimes they break if your unlucky otherwise a good clean usually sorts them out

 

[Peter1450]

Time for a quick update for anyone who's interested...........................had an hour to spare today so thought I'd whip the head off the cool cylinder,it became fairly obvious why it was running cool and my compressor was underperforming.
At some point in it's life it the big end has seized/picked up, looks to me as though the rod was cut and the piston removed aithough it may have snapped, either way there is no third piston hence my under performing compressor!
Here's where I'm hoping someone here can help,would I be able to repair/get spares for the pump ? Do I junk it and get a new pump and if so what would you recommend? Or do I just continue with a nice big tank and an under achieving pump? Cheers Peter

 

[Peter1450]

 

[Peter1450]

This is the offending con rod (whats left of it!)

 

[MattF]

On the plus side, you know that the valves are likely okay. That's definitely a different approach someone has had to sorting the problem, though obviously it appears they've progressed on the keep it working path rather than the sort it properly one. Best to post a photo of the compressor head unit(s) if you can. Might make it easier for suggestions on parts sources.

 

[anjum]

There should be any number of compressor service/ repair guys out there who can advise you as to availability and price of a new piston/ conrod assembly. I bought a piston and conrod assembly recently for an Abac compressor. Came to £95 posted.

 

[Peter1450]

I've done the usual google search ,but as Rednal went bust there doesn't seem to be anyone selling spares . Anyone know what pump manufacturer they would have used circa 2000,that would be a starting point! Will get a picture of the pump over the weekend. Cheers chaps

 

[rtbcomp]

You may be able to get replacement pistons by size.

 

[Peter1450]

Slow update..........heavy weekend! This is the pump, 3 cylinder with only 2 pistons and rods ,any ideas what make and where to get parts? cheers

 

[simplysimon]

Hi Peter

you have a Fusheng D-4 pump
http://211.21.133.246/ASP/cht/products/E_CATALOG/en/NEW PISTON A(sA)-Vn.pdf

parts lists
http://www.airtekltd.com/part_fusheng.htm

I don't think anyone does spares for this make in the UK, but D4s do turn up on ebay now and again.

 

[Woody.v8]

View attachment 48094

Looking at the state of the bearing surface I would check The crank for wear.

 

[octo0072000]

As woody said the crank bearings in the rod look scrap so the crank may be the same hence the botched repair
to keep it going i would be looking for another pump

 

[Peter1450]

As woody said the crank bearings in the rod look scrap so the crank may be the same hence the botched repair
to keep it going i would be looking for another pump

Ok guys will keep an eye out for a pump, as I say it does work but obviously the performance is down on what I was expecting!

 

[simplysimon]

looks like a D-4 on this compressor, the pump should be a straight swap

http://www.ebay.co.uk/itm/331378812238