Heat exchanger zinc

[rwthomas1]

The 3" replaced a 3" so I can't say for sure. The 3" HX is held on to a bracket with large hose clamps on my engine. If its the same for yours, then just get larger clamps and some rubber material like an inner tube to use as padding between the HX and the bracket/clamps. If the hoses are painted gold like the one in your pic well those are likely original and way overdue for replacement anyway. I measured the old HX in the garage and its 13.5" long so maybe they went to a 3" HX to make it a shorter package? I would measure the hose nipples on the 2" HX and confirm that the 3" HX is compatible. Lenco should be able to answer that question for you. I wouldn't touch the pump unless its giving you trouble! Fix one thing before messing with another, or you might end up with new symptoms and not know what caused it. Some new hoses, a new HX and you will be adding enough coolant to make this a bonafide coolant change, and you should be good to go. RT

 

[our38]

Heat Exchanger

I went digging through the old receipts and I purchased my replacement heat exchanger from Lenco. I have the 3" unit, Lenco part number from the invoice is LE299835 and it was a direct replacement for the unit on the 5432. I paid 338.98 back in '07. Its still working just fine.

FWIW, the 3" has more cooling capacity. Do you need it? Good question, I know the 5432 was upgraded to the 3" unit, the M40 which is just a more modern 5432 has the 3" as well. I'm guessing 5432's had a reputation for running hot. Universal increased the size of the heat exchanger from 2" to 3" and they changed the raw water pump from an Oberdorfer to a Sherwood. Thats not to say a 5432 won't run fine with a 2" HX and an Oberdorfer, it may. But the uprated HX and raw water pump increase the capacity of the system and there had to be a reason for it.... Incidentally, if you have an Oberdorfer there is a replacement cam that will double the output and it will almost match the much more expensive Sherwoods output.

I might be the only person on this board that has actually taken a 5432 apart? I had one fail and replaced it with a used engine that was disassembled and thoroughly checked before being regasketed and installed in my boat. I have some "experience" building drag engines and messing with diesel engines and I can tell you the 5432 (its a Kubota) is a very well made and robust engine. The only way you will hurt one is to neglect it. Clean oil, fresh fuel, keep it cool and it will deliver reliable performance for many, many years.

RT

BTW, I got a quote from Lenco today; it was about $270 for the 2" (including shipping), which sounded like a pretty great price. Would the water temperature I'm operating in affect the need for the 3" rather than the 2"? I just checked the water temperature around RI, and it indicated that it's about 71 degrees, but here in Monterey the water temperature is about 59 degrees. Not sure how much difference 12 degrees when the engine is running at 160 degrees. Thanks for the new Lenco #, I'll ask them about it when I call them in the morning.

 

[our38]

Heat Exchanger

The 3" replaced a 3" so I can't say for sure. The 3" HX is held on to a bracket with large hose clamps on my engine. If its the same for yours, then just get larger clamps and some rubber material like an inner tube to use as padding between the HX and the bracket/clamps. If the hoses are painted gold like the one in your pic well those are likely original and way overdue for replacement anyway. I measured the old HX in the garage and its 13.5" long so maybe they went to a 3" HX to make it a shorter package? I would measure the hose nipples on the 2" HX and confirm that the 3" HX is compatible. Lenco should be able to answer that question for you. I wouldn't touch the pump unless its giving you trouble! Fix one thing before messing with another, or you might end up with new symptoms and not know what caused it. Some new hoses, a new HX and you will be adding enough coolant to make this a bonafide coolant change, and you should be good to go. RT

I was just looking on the Lenco site, there is a 5/8" OD on the saltwater-in side of your HX, where mine is 1/2" (I t think this is somehow connected to exhaust). Not sure how far back up the line I'd have to go to change my 1/2" to 5/8". Also, my saltwater-in line is a 3/8" NPT, and yours is 5/8" OD, but I measured the OD of my threaded nipple, and it's 5/8", so I'm good there.

If the 3" fits in the same cradle, I should be able to make it work without too many issues. I'll just have to find something that's 3" diameter and try it out. Thanks.

 

[joe-fran]

think about hoses too

2 winters ago, I pulled my HE out (1987 E 28) and for short money had the local radiator shop dip and clean it.
I replaced the zinc and end plate gasket. It was working fine before - just some PM on my part.
Just a suggestion - while you have the HE out, think about replacing the water hoses going in and out of the HE. I am certain the hoses were original 25 years old on my boat but it was an easy task and some peace of mind

 

[our38]

Heat Exchanger

Well, as Rob mentioned regarding the gold paint, they probably are original AND 32 years old, so I will pull the hoses off and replace with new ones. I found a bottle with a 3" diameter, so I'll head down to the boat later and see how that fits on the cradle, and determine whether or not that requires any modification. Since the newer 3" diameter unit is shorter, I don't expect the new length of 13" to be an issue.

I understand there is an impeller inside the pump that needs to be changed periodically, is that right? If that's the case, then I should locate that and change that as well, while I'm working on the coolant system. It's been at least eleven years since that's been checked as well.

On a side note, if anyone has a battery selector knob that would fit the DC panel of my 1980 E38 hidden in their garage, I be happy to take it off your hands . I haven't been able to locate a knob with a 3/8" bore that would work, and I'm trying to avoid replacing the entire switch on the other side of the panel from the knob, as it looks like it might be epoxied to the other side of the panel. Someone suggested using epoxy and wire inside the back of my existing knob, which I'll try once I order a new HE, as I'll have about a week or so to mess with it.

 

[our38]

Heat Exchanger

Joe, Mark, Rob, thanks for all the input. I ended up ordering a new HE from Lenco; it's about $325 including shipping, and I'll have it in about a week. I'll start measuring and replacing hoses over the next couple days. I also think someone mentioned the water pump ... so I took the cover off and removed the impeller (and was very careful not to pull the shaft out - thanks for that suggestion). The impeller and gasket I ordered are in, so I'll go pick it up this afternoon. There is a cap on the side of the water pump, and when I looked it up, discovered that it's a grease cap; do I need to unscrew that and refill with grease, or should I remove the cap and replace with a new one already full of grease? Do any of you know what this is, or how important it is to replace or refill? I've attached a couple pictures, and it's the silver cap on the side of the pump that I'm talking about. The impeller has been in there for at least eleven years, and the rubber has some cracks, so I'm changing it. My hope is that I can get the new impeller on the shaft without without any difficulty.

 

[Frank Langer]

The new impellor will fit into the pump without trouble--just twist it in, make sure it's all the way in before you put the plate on. I always grease all the surfaces as well with a water resistant grease to ease friction on the impellor at start-up.
The grease cup unscrews easily, but don't drop it into the bilge! I fill mine with a water resistant grease and reinstall. I turn it a bit tighter whenever I'm in the engine area, but at least it should be turned 1/2 turn every 30 engine hours. Mine gets turned more often which keeps the pump lubricated.

Sounds like you are taking all the right steps to get it into good shape!

Frank

 

[rwthomas1]

You're on the right track with all you've asked and done so far. Consider replacing all the hoses, from the seacock to the exhaust elbow. Wouldn't be a bad time to replace the coolant side hoses as well since the HX is out and the coolant is drained. RT

 

[our38]

Coolant hoses

You're on the right track with all you've asked and done so far. Consider replacing all the hoses, from the seacock to the exhaust elbow. Wouldn't be a bad time to replace the coolant side hoses as well since the HX is out and the coolant is drained. RT

I plan to replace all the coolant side hoses, including the ones going to and from the water heater. I hadn't planned to replace them all the way to the seacock, but I suppose you're right, darn. Any thoughts or comments about that grease cup on the water pump?

 

[mherrcat]

Speaking of water heaters, if your heat exchanger was in that kind of shape, your water heater is probably in similar condition. If it is a typical Raritan water heater it also has a zinc anode that is integrated into the hot water outlet. I think replacement cost is $30 - $40. The pressure relief valve can also become encrusted causing it to not re-seat properly if opened and then leak. Or, if you don't really need hot water you could remove the water heater altogether, looping the coolant line to close the circuit. Be careful with those water heaters; don't know if the small Raritan's have a thermostat, but they can put out some seriously scalding water. I removed my water heater several years ago when replacing the fuel tank and have yet to reinstall it.

 

[our38]

Water Heater

Speaking of water heaters, if your heat exchanger was in that kind of shape, your water heater is probably in similar condition. If it is a typical Raritan water heater it also has a zinc anode that is integrated into the hot water outlet. I think replacement cost is $30 - $40. The pressure relief valve can also become encrusted causing it to not re-seat properly if opened and then leak. Or, if you don't really need hot water you could remove the water heater altogether, looping the coolant line to close the circuit. Be careful with those water heaters; don't know if the small Raritan's have a thermostat, but they can put out some seriously scalding water. I removed my water heater several years ago when replacing the fuel tank and have yet to reinstall it.

Thanks Mark, I'll have a look at the water heater today when I go down to replace the impeller.

 

[Loren Beach]

Heater Tank Zinc??

Help me out here. I am not aware of any anode in the old factory water heater that I replaced and none in the new one that I installed many years ago.
It is filled with fresh drinking water.
The engine coolant loop inside carries only the usual mixture of antifreeze and water, i.e. "coolant".

Where does a problem arise?

This is in stark contrast to the H.E. which carries warm outside water (salt or fresh, depending) through it, in quantity.

LB

 

[toddster]

Help me out here. I am not aware of any anode in the old factory water heater that I replaced and none in the new one that I installed many years ago.
It is filled with fresh drinking water.
The engine coolant loop inside carries only the usual mixture of antifreeze and water, i.e. "coolant".

Where does a problem arise?

This is in stark contrast to the H.E. which carries warm outside water (salt or fresh, depending) through it, in quantity.

LB

OK, I just read the (seaward) manual on that last week or so. Anodes are available as an option by calling the factory, but generally they're magnesium, not zinc. The problem is that many of these heaters have lightweight aluminum tanks that have been known to corrode away rather rapidly in areas where the source water has a lot of dissolved solids in it. Portland, no problem. San Diego, big problem.

 

[rwthomas1]

I plan to replace all the coolant side hoses, including the ones going to and from the water heater. I hadn't planned to replace them all the way to the seacock, but I suppose you're right, darn. Any thoughts or comments about that grease cup on the water pump?

I replaced ALL the hoses below the waterline on my E38 when I purchased her. Not knowing the vintage and many were visibly dry rotted, etc. it was the prudent thing to do. Any hose connected to a seacock or critical fluid like coolant, etc. is a candidate for close inspection and replacement. I cannot comment on the grease cup, I have the Sherwood pump and it doesn't have one. There are many folks here with the Oberdorfer, they will have the answer.

RT

 

[our38]

Installed HX and ALL hoses

I replaced ALL the hoses below the waterline on my E38 when I purchased her. Not knowing the vintage and many were visibly dry rotted, etc. it was the prudent thing to do. Any hose connected to a seacock or critical fluid like coolant, etc. is a candidate for close inspection and replacement. I cannot comment on the grease cup, I have the Sherwood pump and it doesn't have one. There are many folks here with the Oberdorfer, they will have the answer.

RT

Well, I installed the new HX and replaced all the hoses, including to the sea-cock. It was starting out to be an exciting day, got everything together, started the engine, was getting water spray in the exhaust - GREAT, then it started to overheat . I rechecked everything, and the only thing I can think of is that after removing the old HX, and it's probably been almost two weeks, the system has been sitting, giving the thermostat time to completely dry out and freeze. I'm not a diesel mechanic person, and haven't worked on engines in about 40 years, but I seem to recall a similar issue when I was rebuilding a 57 Chevy when I was a kid. Back then, thermostats were easy to remove and replace. Now, with this 1980 Universal 5432, I'm not so sure how easy that's going to be to replace.

If anyone thinks I should look at something else, please let me know. If anyone has any other suggestions, please let me know. I'm including a picture of where I think I can find the thermostat. If someone knows that it's located somewhere else, please let me know. I'll find out for sure on Sunday.

 

[mherrcat]

I doubt it is the thermostat. Before you pull it (and that is the housing you have pictured) check that the exhaust manifold is full of coolant. Then start the engine and loosen (but don't remove) that plug on top of the thermostat housing to bleed air from the coolant circuit; tighten the plug when only coolant and no bubbles come out. If you have to remove the thermostat, note its orientation in the housing before removing; there may be a mark on the t-stat indicating which side faces forward. You'll probably need a new t-stat gasket as well.

 

[our38]

Thermostat

I doubt it is the thermostat. Before you pull it (and that is the housing you have pictured) check that the exhaust manifold is full of coolant. Then start the engine and loosen (but don't remove) that plug on top of the thermostat housing to bleed air from the coolant circuit; tighten the plug when only coolant and no bubbles come out. If you have to remove the thermostat, note its orientation in the housing before removing; there may be a mark on the t-stat indicating which side faces forward. You'll probably need a new t-stat gasket as well.

Thanks Mark. I'll try to get down there this morning and try that. I wasn't sure what that square-head bolt was for on top of the thermostat housing. If I do need to replace the thermostat AND gasket, will it be easy to locate a source for a new one? (in the event that...)

When it overheated the first time, I was constantly going back and forth looking for leaks at all the hoses, checking for spay coming out of the exhaust, and watching the temperature gauge. With the previous HX the temperature never reached 160, so when it started to slowly rise to 160 I felt pretty good. But then within only a few minutes, it passed 160, then passed 180, headed to the red line around 200, so I quickly shut everything off and let it cool down. Once cooled down, I repeated the process, but with the fill cap on the manifold removed, to see if I could tell wether or not the coolant level went down once the thermostat opened, and it never did. I didn't think about trapped air, but there could certainly be a lot of that since it sat for two weeks.

Was it you, or Rob, that had noted that you have a repair manual for the 5432? Is there a 5432 repair manual PDF floating around out there somewhere that I can just download?

 

[joe-fran]

overheat

probably not the thermstat. When I replaced all my hoses on my E28 ,had same problem. It's most probably some air in the hoses preventing a good circulation of coolant. Some of your hoses may be a little high for the water pump to properly get primed. I found a good link on a catalina 34 site that showed me what to do and it worked fine. I'll try to locate it for you. I think I saved it on my work PC.

Joe

 

[our38]

Possible thermostat issues

probably not the thermstat. When I replaced all my hoses on my E28 ,had same problem. It's most probably some air in the hoses preventing a good circulation of coolant. Some of your hoses may be a little high for the water pump to properly get primed. I found a good link on a catalina 34 site that showed me what to do and it worked fine. I'll try to locate it for you. I think I saved it on my work PC.

Joe

Thanks Joe. I'll try to bleed the air as Mark suggested, but if that doesn't work, I'll look forward to seeing that link of yours. I'm just not sure if I'm supposed to wait until the engine gets hot before trying to bleed the air, or just get the engine started, then try bleeding the air ??????

I'll try just starting the engine and bleeding air before the engine gets warm 1st, since that's the quickest and easiest. If I can get down there today, I'll post the results this evening. If it works, I'm going sailing

 

[mherrcat]

Just start the engine and loosen the plug; once the engine is running and the coolant is circulating I don't think the engine has to be up to temp. Marine Diesel Direct (Toressen Marine) should have t-stat and gasket; MDD is pricey however, so it is worth searching for other sources; I found TDC Equipment in Huntington Beach, relatively close to me, to be better. If you can cross reference the t-stat part number or engine block to the Kubota tractor model, a tractor supply store might have even better pricing. Someone around here put together a cross reference list at one time. MDD has manuals for the Universal engines I believe. I usually look up part numbers on their website and try to find better deals elsewhere.