Checked my maintenance schedule for my tm and they say you should clean out the hx every 500 hours.. I haven't done it yet and I'm at about 2,100. :shock: Looks like this is going to be a pita? On a scale of 1 to 10 what's the difficulty? Here is a pic.:
Heat exchange clean out??
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travis montgomery
Member
- Joined
- Nov 21, 2006
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- 20
is it still working[center:3lqnd90f][/center:3lqnd90f]
C
Chris Sheldon
Guest
Keith,
It shouldn't be too difficult; once you take off the fittings and the 6 bolts, it (they) should slide right out.
If 10 is the hardest, I would give this job about a 4 or 5....You can do eeeeeeeet!
Chris
It shouldn't be too difficult; once you take off the fittings and the 6 bolts, it (they) should slide right out.
If 10 is the hardest, I would give this job about a 4 or 5....You can do eeeeeeeet!
Chris
How is the access to those "6" bolts...I see a fair bit of work there on an installed against the headache cage machine.
The blow up, looks like Keith has room for one more HX core to be added....probably not higher heat, but more volume of heated water....this same "box" must be used on larger units.
The blow up, looks like Keith has room for one more HX core to be added....probably not higher heat, but more volume of heated water....this same "box" must be used on larger units.
C
Chris Sheldon
Guest
Greenie said:
No doubt Greenie. But that is poetic justice for a guy that would have his machine installed up against the bulkhead! I hate those friggin' things and adivise all of my customers to take them out before I install their machine.
But then again, I look it at from a mechanic's point-of-view.
C
Chris Sheldon
Guest
They should just slide out once you remove the bolts and plumbing. If they have been leaking for a long time they can be a bear to get out because of all the rust, but from the outside at least, yours don't look too bad.
You should be able to re-use the gaskets. If they are bad I can give you some ideas on how to seal the HE's wihtout the OEM gaskets.
Quit being a wuss already and take them out! ha!
-Chris
You should be able to re-use the gaskets. If they are bad I can give you some ideas on how to seal the HE's wihtout the OEM gaskets.
Quit being a wuss already and take them out! ha!
-Chris
Shane T
Member
Keith, Be sure and take some pic of the dirty exchangers and the inside of of that unit. I'd like to what kind of shape they were in.
Duane Oxley
Moon Unit
I worked on one about a month ago. It was private- labeled, but the same system. The exchanger (#11) closer to the exhaust from the motor / blower is a high pressure one and is the final exchanger before the system leaves the system. The one behind it (#28) is lower pressure and is used to preheat the water tank.
The copper inlet to the low pressure exchanger corroded and started leaking, so it had to be removed and inspected, repaired if possible.
Removing the exchangers was pretty straightforward, actually. Loosen and remove the plumbing and remove the (6) 1/4"-20 bolts, then slide the exchangers out.
The main problem with the job was that the bolts kept shearing off, due to corrosion from the leak. This shouldn't be the case on your system. But I highly recommend that you apply some marine grade anti seize compound onto the bolts before screwing them back in when you re-assemble the system.
The gaskets appeared to be high temperature silicone. They weren't cut from a sheet, but were a liquid that was used to make the seal. You can probably re-use them, but just in case, it wouldn't hurt to use some liquid to make sure they fit tightly upon reinstall.
One more thing: There are rubber vibration dampeners under the "exchangers" (heater cores, actually), to keep them from being torn up by vibration as the system runs. They came loose and had to be re- positioned, then moved around some upon re-install of the exchangers. Maybe they were originally glued down. I'm not so sure. But it wouldn't hurt to glue them in place with some quick- dry contact cement first, if they're loose.
The copper inlet to the low pressure exchanger corroded and started leaking, so it had to be removed and inspected, repaired if possible.
Removing the exchangers was pretty straightforward, actually. Loosen and remove the plumbing and remove the (6) 1/4"-20 bolts, then slide the exchangers out.
The main problem with the job was that the bolts kept shearing off, due to corrosion from the leak. This shouldn't be the case on your system. But I highly recommend that you apply some marine grade anti seize compound onto the bolts before screwing them back in when you re-assemble the system.
The gaskets appeared to be high temperature silicone. They weren't cut from a sheet, but were a liquid that was used to make the seal. You can probably re-use them, but just in case, it wouldn't hurt to use some liquid to make sure they fit tightly upon reinstall.
One more thing: There are rubber vibration dampeners under the "exchangers" (heater cores, actually), to keep them from being torn up by vibration as the system runs. They came loose and had to be re- positioned, then moved around some upon re-install of the exchangers. Maybe they were originally glued down. I'm not so sure. But it wouldn't hurt to glue them in place with some quick- dry contact cement first, if they're loose.
Shane T
Member
I don't know what it's suppose to look like but seems to me that would be very restrictive. Bet your vac will be a lot better once you clean it.
Yeah, I really don't know what it should look like either. Better vac you say... That would be great!
What do you do to clean these just water? Air? Brake cleaner ? Well brake cleaner is flamable probably not he best choice.
Thanks,
Keith
What do you do to clean these just water? Air? Brake cleaner ? Well brake cleaner is flamable probably not he best choice.
Thanks,
Keith
Eric Valentine
Member
I would venture to say that brake cleaner would dissolve the soot and any oily crud better. Coil cleaner for air conditioners might work too.
I think I am going to go with the brake cleaner and let them sit for a while.. It's probably just acetone and will evaporate quickly..
I wonder if I could move one of those heat exchangers closer to the exhaust, what do you think? I think I might gain more heat? At least maybe it will heat my water faster at start up????
I wonder if I could move one of those heat exchangers closer to the exhaust, what do you think? I think I might gain more heat? At least maybe it will heat my water faster at start up????
Shane T
Member
There may be a reason they haven't put in any closer to the engine exhaust. It may isolate to much heat in one area of the exchanger if its closer. I don't know how those exchangers are made.
C
Chris Sheldon
Guest
Oh crap Keith! That one is almost totally obstructed!
Once you get it all cleaned out and installed I bet your machine will run like new again! Better heat, vac, etc.
An easy way to clean those fins is to go to NAPA and buy what's called a "radiator comb"; I use mine to not only clean H.E.'s and radiators but to straighten any bent fins as well.
Once you get it all cleaned out and installed I bet your machine will run like new again! Better heat, vac, etc.
An easy way to clean those fins is to go to NAPA and buy what's called a "radiator comb"; I use mine to not only clean H.E.'s and radiators but to straighten any bent fins as well.
Shane T
Member
I bet you don't let it go so long next time!
I think I'll be doing it every 500-750 hours now.... that was bad! I have 2 rentals tomorrow can't wait to see the difference! I think this might have had something to do with my exhaust issues also... Just a thought.
Edit: I was thinking the same thing with that comb but the napa by me had to order... I'll have one for the next time.
Thanks all for the help!
Keith
Edit: I was thinking the same thing with that comb but the napa by me had to order... I'll have one for the next time.
Thanks all for the help!
Keith
I think I gained at least 40 degrees after cleaning them out... Thing I have noticed is a rubber burning smell. Belts are fine... My disty gave me rubber gaskets instead of the type that came stock. You think rubber will be able to withstand the heat or is that what I smell burning?
