Repairing Aluminum Coolant Fittings

[dirtrack49]

Just got through taking off all of the cooling related items on the front of my 230SL due to coolant leaks.

While cleaning up the numerous hose fittings, especially on the water pump housing, I see there are several areas of rather deep pitting or cratering of the aluminum. Although I have seen this on other vehicles and have simply done nothing other than minor cleaning and replacing of the various rubber hoses, I feel that since I have things apart, there might be a way of cleaning this damage up? My first thought is to use an epoxy like JB Weld and try and fill in the damaged areas.

Anyone have any experience or suggestions on what might be a good solution?

TIA

[kampala]

have not tried it --- but remembered the video.


https://www.youtube.com/watch?v=mxM-EXBx-8o

[dirtrack49]

Thanks Oz, great video. I would not have thought about using an acid cleaner on the aluminum prior to applying the JB Weld epoxy.

A little off topic, but does anyone know what torque value is given for the water pump housing, water pump and cooling fan bolts? I don't think my vehicle had ever been taken apart. I know for sure that the bypass hose was original. The water pump housing and water pump bolts were very easy to back off as if they were very low torque values. The three bolts on the six bladed fan were on very tight, almost like they had used Loctite.

[Shvegel]

I just checked maximum temp of JB weld and it is 500F so you should be OK.  If possible  would bead blast rather than chemically clean the surface.  most castings are fairly porous and any moisture or acids may affect bonding.

[wwheeler]

I have had the same issue. While this is a 220SE part, same problem. I took this to a local welder who mainly does aerospace work. This guy is magic with a welder. See before and after shot. I paid about $60 bucks for this. I had to clean it up after, but what a deal. Let me know if you want the name. They are near Dallas.

[Richard S]

Does anyone know what acid Ken used to clean the aluminum part?

[dirtrack49]

Thanks Shvegel and Wallace for the comeback. Bead blasting would probably be the ideal, however I don't have the capability at home. The welding work that Wallace had done is really nice, however, your situation was a little more severe than what I am dealing with. I have an excellent welder near where I live, and if need be, I will take your advice. Thanks.
Maybe using vinegar, lemon, or citric acid might be worthwhile vs. using something more caustic like muriatic acid or some of the chemicals on the market for stripping corrosion off of aluminum surfaces? I am thinking that I will try digging out the bad pits and cleaning them up with vinegar. After that, I will go ahead and put some JB Weld in the craters and sand them off. After they cure up, I will try and see if I can pull them out. I will let everyone know what the results are.
Still one thing outstanding, can anyone give me some torque values on the water pump, water pump housing, thermostat housing to block and the top of the thermostat housing?
TIA

[wwheeler]

On the JB weld, be sure to use one that is made for water contact. I believe there is a Marine version available.

[dirtrack49]

There is one formula made for water tanks, however, I have used the regular original version on would you believe a pool pump intake filter that has been going strong for the past 10 years. That intake had split open in several locations due to a hard freeze. I must admit it is pretty hard to beat the capabilities of their epoxy formulas. I used the original version to repair my coolant recovery tank bracket and everything is well.

Can anyone tell me where I can find or let me know what the torque values for the fan blade, water pump, water pump housing and thermostat housing should be???

TIA

[tel76]

If you look in the tech: section you will find the torque settings for different types of bolts.
The ones you are wanting to tighten with experience you know how tight they should be.

[dirtrack49]

OK, so I went and filled all of the corrosion holes on my water pump housing and thermostat housing. I used regular JB Weld regular formula since it has a long cure time of 15 hours.

In the video, they show using some type of acid after cleaning up the affected area. I simply sprayed on some carburetor cleaner and wiped off the areas with a rag. So far, it looks ok with the exception that it takes a lot of sanding to smooth out the JB Weld.

I also found that if you don't let the epoxy set up for about 15 minutes, if will sag and you will end up repeating the process.

If I were to do it again, I would most definitely spread the epoxy completely around the entire circumference of the fitting. I only put the epoxy in the obvious locations that needed to be filled.

Once I finish the job and put everything back together, I will let everyone know what I have had for results.

[Shvegel]

Just in case anyone comes back to this thread with the same issue regular JB weld is fine.  Regular JB weld contains steel powder so it can get rusty if exposed to salt and/or water after sanding but since Coolant contains anti-corrosives it is AOK.