Speedaire dryer repair and/or DIY dryer?

nine4gmc · Feb 9, 2015

Hey guys, I got this Speedaire dryer model number 3Z528 for free today and I'm trying to see if anyone is familiar with these units. The cord was shot so I took off the cover and found a plug inside that bypasses the external cord. After plugging it in, the cooling fan comes on but the compressor does not seem to run. :dunno:

The system looks quite simple, there is a compressor with a cooling thingy in the center of the in/out air supply line coil. The in/out air supply coil has no drain or anything, it's just copper tubing that makes a coil inside the machine and has spray foam insulation covering it and the cooling thingy that comes from the compressor.

I'm wondering if this could be a simple/cheap repair or if I could use a water bottle cooler like below to make my own dryer? I've taken numerous water coolers apart and they have the same setup inside, minus the copper coil for the air supply. I'm pretty sure they will work but wanted to see if anyone has tried it or could help me diagnose this machine first.

nine4gmc · Feb 9, 2015

After letting it run for a while, the compressor is warm to the touch but the cooler part is room temp still. What type of freon does this thing take? I may pull a vacuum on it and see if I can fill it up.

zkling · Feb 9, 2015

Hard to tell from the pics, but does the system have a port on it or is it sealed? It should have a sticker on the unit listing refrigerant type, weight and all the info needed to refill the unit. It is most likely R-12 under 10oz and under 40psi.

nine4gmc · Feb 9, 2015

Sorry for the ****** pic, try this one. I could only find one port, pencil is pointing at it. I found the refrigerant type on the outside label, it's a 1/6 hp and requires 6.5 oz of R-12. Can this compressor be retrofitted with R134 like an automobile?

jakemac · Feb 9, 2015

Take it to your mechanic and have him do a pressure test on it. If it doesn't have any leaks you can ask him about converting it to R134. :dunno:

nine4gmc · Feb 9, 2015

But Jake, I am my mechanic.

jakemac · Feb 9, 2015

How's that workin' out for ya ? :lol:

nine4gmc · Feb 9, 2015

Actually pretty well, I swapped out a 6 cyl and trans for a newer v8 and retrofitted the old R-12 to 134, changed the ball joints, u-joints, shocks, dash, wire harness, etc... Never "mechanic'd" on a hermetically sealed compressor air dryer though. :dunno:

jakemac · Feb 9, 2015

zkling · Feb 9, 2015

After reading the first post properly

: I'd start by checking the compressor control circuit to make sure it is getting voltage. Getting the compressor running is priority #1. Check the start cap.

nine4gmc · Feb 9, 2015

Read post #2, I'm pretty sure it's running Z, it's getting hot after having it plugged in for a while.

zkling · Feb 9, 2015

Put a R12 compatible gauge set on the port. See, what if anything is in there. That second pic helps a lot, that thing looks to have seen much better days.

redmondjp · Feb 9, 2015

Can't change to R134 without also changing the compressor oil. I'd try to find some R12 - my hunch is over time some has leaked out of that port and the system is low. Do a pressure test as advised above first.

6.5oz for a full charge is less than a half-can. It's not cheap but it's still available. Ask your buddies, maybe one of them has an old dust-covered can of R12 on a back shelf somewhere.

nine4gmc · Feb 9, 2015

Thanks Z and redmondjp, I'll dig out my old gauge set and check it out.
As with most cheap/free things I get, it will definitely need refurbing if I can get it going. Sadly, I threw the end panels of the case in the scrap pile we took last week without realizing what they were until I dug the unit out today. I'll have to fab those up too, along with some new insulation and spray foam if it works. Rats used the old foam for a nice bed...

48RON54 · Feb 9, 2015

if you end up restoring it, I'd be interested in seeing pics of that

mikebaker1129 · Feb 9, 2015

nine4gmc said:
Sorry for the ****** pic, try this one. I could only find one port, pencil is pointing at it. I found the refrigerant type on the outside label, it's a 1/6 hp and requires 6.5 oz of R-12. Can this compressor be retrofitted with R134 like an automobile?

Short answer is NO.

mikebaker1129 · Feb 9, 2015

Look for an oily spot and you will most likely find your leak or pressure it up with 120 psi of nitrogen or argon and use soapy water to look for the leak. If you find it in the copper , braze it up with a torch and some 15% silver solder. Then pull a deep vaccum and recharge with R12.
If you know a refer guy have him do it for a 12 pack.

nine4gmc · Feb 9, 2015

mikebaker1129 said:
Short answer is NO.

What about the long answer?

2oolhound · Feb 10, 2015

Have you looked on line for a manual? Last time I looked at a manual for one of those I was impressed with the amount of detail they explained the design and function of each component and the trouble shooting info they gave you.

Dragoonmc · Feb 10, 2015

Sounds to me like the start cap is bad if stuff is getting warm I'd just replace it to be safe should be much money

redmondjp · Feb 10, 2015

Dragoonmc said:
Sounds to me like the start cap is bad if stuff is getting warm I'd just replace it to be safe should be much money

Those hermetic compressors are so quiet that it is very difficult to tell if they are running or not. Most older ones use a start relay (actually a bimetallic contact) to momentarily energize the starting winding. If the compressor doesn't start, you will hear a 'click' a couple of seconds after energizing the unit (the bimetallic-controlled contact in the start circuit opening due to current flowing too long meaning that the motor didn't start). Once the overload cools off, it will reclose and attempt to restart the compressor.

And it's normal for the compressor to be warm when running.

Oh, one other important tip to the OP when you are working on this unit: after having the compressor running, allow at least 10 minutes before trying to start it again. This applies to any piece of equipment (window A/C unit, home refrigerator or freezer, etc) with a hermetic compressor in it.

The reason for this 10-minute off-period is to allow the high and low side pressures to equalize. There is no unloader valve on these systems! They can't start against high pressure in the high side of the refrigerant loop.

Milton Shaw · Feb 10, 2015

Also a simple hand on pipes will tell if R12 is flowing. The small line out of the compressor should be warm or hot and the larger line in should be cool. The compressor will heat up and feel warm to the touch without running as the windings heat up while its trying to start.

mikebaker1129 · Feb 10, 2015

nine4gmc said:
What about the long answer?

The mineral oil in the R12 unit is not compatible with R134A. The charge on a small refer system is very critical and shoul be weighed in with a scale unlike charging an air conditioning unit where in the ballpark is generally good enough.
You know any refrigeration guys? Not all A/ C guys can do refrigeration.
If you were closer to Houston I would fix you up.

nine4gmc · Feb 10, 2015

Thanks for all the replies and thanks for the offer Mike, wish I were in Houston for more reasons than one!! I lived in Dallas back in 2k and would love to be back out there one day...unfortunately I do not know any refrigeration guys locally. I do have a postal scale, measuring glasses, vacuum pump and a set of r134 gauges on hand and also set of R-12 gauges around here somewhere if that helps.

Milton, neither pipe changes temp, just the compressor gets pretty warm after running a while(between 5&30 mins, I walked away and don't know exactly how long). On the few water coolers I've destroyed, I have tested a few and have the general understanding how this thing should work now, I'm just not well versed in frige talk. :lol:

I'll get out there tomorrow and check it out better, find out if there is any refrigerant, pump actually running, etc.
thanks again guys for all your help!

redmondjp · Feb 10, 2015

Here's a trick that an old-time HVAC technician taught me and I have been successfully using for the past 20 years: add freon to the system until the low-side (suction) pipe at the compressor just starts to get cold.

No scale required.

Sounds like there is essentially zero freon left. Unless there is mechanical damage to the system somewhere, my money is on that fill/test port leaking (has a schrader valve in it most likely which can be removed and replaced).

nine4gmc · Feb 10, 2015

If its empty when I check it, I'll change out the schrader valve and pull a vacuum on it and see what happens.

Thanks again Redmondjp!

nine4gmc · Feb 12, 2015

Ok, I checked for a shrader valve and there is not one in the hole. No threads for one either so idk if it ever had one. The cap on top of that fitting covers what looks like a square valve handle that possibly opens/closes an internal valve inside the fitting but it's locked tight right now so I have it soaking in penetrant to free it up. I'm assuming there is no refrigerant in the system at this point.

nine4gmc · Feb 13, 2015

Picture added to previous post.

redmondjp · Feb 13, 2015

Cool - a service valve, just like Ford use to use on their York A/C compressors such as on the 1971 LTD I grew up in. You connect gauge set first, and then open the valve.

1950mercury · Feb 13, 2015

nine4gmc said:
Ok, I checked for a shrader valve and there is not one in the hole. No threads for one either so idk if it ever had one. The cap on top of that fitting covers what looks like a square valve handle that possibly opens/closes an internal valve inside the fitting but it's locked tight right now so I have it soaking in penetrant to free it up. I'm assuming there is no refrigerant in the system at this point.

That should be an excuse to get a valve wrench.

MacMcMacmac · Feb 13, 2015

Why not drop in some R-12 replacement for automobile AC systems. I put Duracool in my brother's Taurus two years ago and we had snowflakes coming out of the vents in May. It was amazingly cold.

Naturally, you do not want it that cold to dry the air, but a little judgement should see your dryer working fine with it, if it is salvageable mechanically that is.

nine4gmc · Feb 13, 2015

I was unaware of Duracool, I'll check it out this weekend. Thanks for posting!

1950Mercury, I keep seeing the valve wrenches in the garage sale thread but have yet to see one in the wild, my luck I will find one right after I get this thing fixed... :lol_hitti

aaron77 · Apr 24, 2015

Any updates on this?

Speedaire dryer repair and/or DIY dryer?

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