Removal of Heat Exchanger Core

Due to failure of a bearing in the circulatory water pump on our Volvo TMD30A I had to remove the heat exchanger to replace the pump & while off was told it was a good idea to rebuild the HE with new o-rings, seals & thermostats. In a perfect world the core is supposed to slide out for cleaning & installation of new o-rings at either end to form the seals between the raw water & coolant. The core is copper & the casting is aluminum I think, it’s not steel. I’ve been told to be very gentle with the copper core so I don’t have to drop a boat dollar for a new one.

The core is straight at one end & flared at the other thus it only moves one way.

What I’ve done so far is soaked everything in vinegar to loosen any corrosion, gently tap the straight end & heat with a gun & gently tap., So far no movement.

Anyone had a creditable idea to loosen the core from the casting?

Maybe try to soak it in a diluted solution of CLR?

You might want to take it to a radiator shop and have them boil it out and remove the tube bundle for you. They are very easy to damage if you don't have the right tools.

If you're lucky, the tube bundle may be copper nickel and will last a bit longer. I don't see a replacement listed for the bundle at Manifold Wearhouse, so maybe it's a dealer only item??

Larry B

HJ - If you are just heating the area around the core, this will make it more difficult to remove as it expands the core,making it tighter.
The trick is to heat the outside component (the heat exchanger body), while keeping the inside component (the core) cool. Easier said than done.
If it fits -you could try to put the whole lot in the oven for an hour at 200F, then cool the core by pouring water through it. Then try tapping before the temperature of the two components equalize again.

Steve

Don't risk damaging it..straight to the local radiator shop. Quick & inexpensive job for them to remove and clean.

Success...a buddy of mine with excellent mechanical skills plus the advise of a Volvo mechanic & radiator shop tech, we build a press of sorts using two bar clamps & appropriate blocks to applied pressure to the core for a couple of hrs. Monkey Spit was squirted in what was assumed to be the "problem" areas. One moderate wack with a hammer & the core jumped 1/8". Another wack = 1/4", final wack & it was free. After soaking in vinegar, scrubbing with a brass brush & sanding areas of corrosion the core looks very serviceable.

The Volvo mechanic said old coolant will produce such problems, something breaks down & allowing corrosion to build between the AL housing & the brass core. Said to change it completely every 4 yrs.