Radiator replacement questions


I would have someone competent do a complete cooling system check, INCLUDING testing the temp gauge and warning system. I have spend considerble time chasing cooling system problems that turned out to be gauge/sender problems. It also sounds like you may have an airlock problem. When you do/have done a thorough test, do a complete bleed as well (Bently)


Capt. Mike

Guideline #2: The Bentley manual is required for use on the site.

There is one basic diagnosis that is too often neglected in considering radiator replacement. Take the temperature of the coolant going into the radiator and then coming out. This has become easy with the new digital infared thermometers on the market (as low as $80) but can still be accomplished with standard thermometers (tape to hose at entrance & exit) since you're looking for differential more than not exact numbers. The infared's also allow you to scan all of the radiator core to look for hot or cold spots to indicate less than full uniform flow. [See Electronic Diagnositic Tools topic in the TOOLS forum.]

Regarding the opinion that a flush "won't solve the problem" bear in mind that new technologies in radiator shops have come a long way. yes, the "flush" from a discount auto store may not do it, but You can remove a radiator and a properly equipped specialty shop can do wonders that a regular mechanical shop can't. It's worth getting a 2nd opinion -- after you've done the temp tests.

Beer Westy

New member
Alternative Method for Cooling System Draining?

Well I didn't really need the radiator diagnosis Capt Mike describes previously, a nice fountain of green fluid sprays from the front of the van after a short run on the freeway. Easily traced to the deteriorated and rusty lower portions of the radiator. Seeing how the 85 Vanagon Full Camper (no a/c and no rear heater) is new to me, I thought a full coolant system drain, flush, fill might be good maintenance. I read Bentley (section 19.15) about how to drain the coolant from each of the cylinders. However, the Bentley does not describe or illustrate the metal shroud under each head. I am hesitant to remove the shroud as it is secured in place by the same bolts holding the exhaust to the head; and these bolts are not looking like they will come out easy or without opening a bigger project. I have a new radiator, fan switch for the radiator, and some of the rubber hoses to replace those that look tired. I don't have a thermostat or coolant pump, or the requisite gaskets. Is there a method to a) flush the system without removing the metal shrouds under the heads or thermostat; or b) drain the system without removing the metal shrouds or thermostat. I would like to perform good maintenance without opening the proverbial can and increasing the scope on my simple radiator replacement project.

So far I am feeling confident on the coolant system bleeding, based on reading the tips provided in other sections of this forum. Thanks for the help and guidance.


Capt. Mike

Of course, you don't have to drain the system to change the radiator -- just that section forward. But you should never change radiators without a flush and coolant change of the system since you want to clear any contaminants in the coolant as well as get a fresh, corrosive & particulate-free coolant in your new radiator. Since you are removing a corroded object, it's possible it has or will shed additional particles into the system. As a result, there is no alternate to draining at the heads -- that becomes your lowest point and even then needs help of jacking the front up extra.

However, that is not a big job. You'll have to remove one bolt & one nut each side that hold the exhaust pipes to the manifold, but that isn't a big deal -- just soak them a couple of days in repeat applications of PB Blaster (See SUPPLIERS forum). If well rusted, you'll find an impact wrench often works better than a hand wrench -- just don't crank the power up. The idea is the hammering effect shakes loose rust and breaks the seal, plus impact wrenches usually don't work up off the head of the bolt and round it off. A 3/8" drive, rachet style of 35-45 ft. lbs. capacity should suffice. The two bolts that hold the bottom of the deflector to the engine case shouldn't be a problem, either. They are thread into aluminum so don't rust to the same degree. You can do the same PB Blaster on them. When you do get the exhuast nuts and bolts off, you should inspect and replace if necessary. Copper nuts and stainless bolts will make it easier next time -- this needs to be done every 2 years -- and always use anti-sieze when re-installing.

When finished with the flush & replace coolant cycles (own topic) and replacing the plugs for the last time, replace the copper seals under the drain plugs, left & right. The flushing will be the long & tedious part; see the "Clearing the muddy waters . . ." topic in the TIPS forum.
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New member
Radiator removal issues '86 syncro

Hi all. I'm having sime MAJOR difficulties removing the spare tire carrier upper retainer spring/hinge pin in my '86 syncro to remove the rad. I've removed those little clips and have pulled, pried and cursed the ends that run through the hinge and will not come out. There is no way for me to remove old or install new rad unless I can get through this. Don't want to cut-as retainer is important to keeping tire in place in holder....
Any advice would be greatly appreciated.


Weekend Wrench

New member
I had similar difficulty and achieved success by using a nail punch against the end of the steel tube to push it out through the support piece. I prepped the operation by spraying the area with PB. One side came out more easily than the other side. The nail punch was the secret weapon.

My new radiator is installed and running nicely.

Skip (Weekend Wrench)
'84 Westy