Technical Advice: Eng/Trans/Clutch

Warning! Working on cars takes patience, knowledge, skill, proper tools, proper safety equipment, common sense, and an understanding of automotive maintenance, repair, and theory. Working on cars can be dangerous and even lethal. Working on cars can make problems worse, can cause new problems and can even damage the car. Cars can fall off jacks and kill you. They can crash and kill you and others when you fail to repair them properly.

My advice on these pages is just that, advice. I am not trying to re-write the repair manuals, nor am I detailing the "only" way to do something. I am merely showing what has worked for me.

In following this advice you are doing so at your own risk.

Cooling System:

The America and all other ADO-16's, as well as the Mini (ADO-15), use a radiator that is turned sideways to the airflow entering the engine compartment. Not a very good idea if you want to keep an engine cool. If that weren't enough of an issue, the radiator fan mounted on the front of the water pump, actually pushes air through the radiator from the engine side. Thus, airflow comes into the engine compartment through the front grill opening and is then blown through the radiator and out the left inner fender over the left tire. An additional problem is that since the fan is basically "sucking" air from around the engine block (the back side of which has a cast iron exhaust manifold)....the air moving throught the radiator is already hot. This is especially critical when you're stuck in stop-and-go traffic, or climbing a long grade at a slower speed. Engine temps begin to rise, and that increases the tempurature of the air that is blown through the radiator.

All this aside, the system does work, even in it's most stock configurations. However, there are plenty of improvements that are both economical and easy to perform. Thanks to the survival of the Mini, there are upgraded radiator fans available, as well as upgraded, "High-Flow" water pumps. Both are well worth the money and effort.

An 11 blade plastic fan is available which has 1-1/2" wide fan blades. Approximately $30. The original fans usually had 1-1/4" wide blades and are less efficient. Especially the early metal fans found on the 1968 and 1969 models.

A 6 blade metal "Tropical" fan is also available. These make a bit more noise, but they move a lot of air.

A note on fan blade installation:

The concave side of the fan blades face the radiator.

Like this: (<---------This side toward radiator!

The "High-Flow" water pump has a cast impeller that is almost a 1/2" deeper than the standard water pump impeller. Plus, it has a closed back surface so it doesn't cavitate at higher revs. Approximately $40.

I have installed both (the upgraded fan and waterpump) on my own car, and am amazed at the difference. Now, no matter what the driving conditions, high speed freeway, stop-and-go freeway traffic in Los Angeles, climbing long grades, long hours of continuous driving, the car stays at normal operating temps. I've had it in as high as 105*F weather, on the freeway and in stop-and-go traffic, and it did fine.

Diagnosing Overheating:

If you are trying to diagnose an overheating problem, as in all diagnostics, start simple.

-Verify that the coolant in the radiator is actually getting as hot as the gauge says.

-Use a cooking thermometer that is properly calibrated to check the coolant tempurature. To calibrate, combine ice and water in a glass with the thermometer. Let stand for 10 minutes. Check thermometer's reading. It should read 32*F because ice and water will maintain that tempurature. Adjust the nut on the back thermometer to move the needle to read correctly.

-Make sure that all tune-up related items are dialed in.....ignition timing....fuel mixture....valve timing.

-Make sure you don't have a brake caliper or rear brake shoes that are hanging up and staying "on."

-Make sure that the temp sensor in the cylinder head, near the #1 Spark Plug hole, has a red colored insulator in the body of the sensor. If it's black or green, the gauge in the dash will always read high. Guess how I learned this?

-Make sure the fan is on the right way. See the above diagram. The fan will still blow air in the same direction, but it will be much less efficient.

Radiator Cap & Coolant Tank Cap:

-Make sure you have the correct radiator caps installed and that they are in the right positions. The "Blanking" Cap goes on the radiator. The 13lb. pressure cap goes on the coolant recovery tank down on the front valance. If these are reversed or, their seals are bad, the cooling system's "Thermo-syphon" will not work and the radiator will continually loose coolant. Sounds silly, but it's actually a big deal on these cars. Remember, you're only working with 1 gallon of coolant and a radiator that is just big enough to do the job. Any deviations will cause problems.

-Don't use more than about 25% coolant mix with water. Unless the car will be submitted to freezing tempuratures. Any coolant to water ratio past 25% will hinder the water's ability to dissapate heat. The cooling system uses 1 gallon, so mix 1 quart of anti-freeze with 3 quarts of water. I like to use distilled water. Less minerals to corrode the radiator.

-Back flush the radiator and heater core with some high pressure water, from your garden hose. Flush both until the water comes out clear.

Thermostat:

-Make sure that the engine thermostat is rated at 180F/80C. If it's of questionable age, replace it. They are cheap and they are the same size as Chevy's 350 V-8 engine, so you can get a thermostat anywhere. Try to find the "Mr. Gasket heavy duty/high flow" thermostat shown above. It's about $13 and well worth getting. Email me if you can't find one.

-Check for a blown headgasket. The easiest way (if you don't see air bubbles in the coolant with the engine running) is to go to shop that has a exhaust gas sniffer. Have them "sniff" the steam coming out of the open radiator filler neck. If their sniffer picks up exhaust gas fumes (Carbon Monoxide and Hydro Carbon), then you have a blown gasket. All radiator shops will also have a chemical "sniff" test using a dye solution.

If everything is in order and you're still experiencing overheating, then I'd say it's time to invest in the "High-Flow" water pump and the improved fan. Also, since the radiator has to be removed for this job, I would strongly suggest replacing all the coolant hoses and consider having the radiator "rodded" out at the local radiator repair shop.

Always work on the cooling system as just that......a system. It's really the last thing you want to have any issues with, even if you only drive short distances.

Tempurature Gauge Readings:

If you still have the stock in dash mounted tempurature gauge, maybe you'd like to know what the needle positions correlate to in actual tempurature.

The beginning edge of the white box is approximately 120*F

The middle of the white box, needle pointing straight down, is 175*F

These readings were sampled using a calibrated thermometer. I have not yet tested the reading at the upper end of the white box, but will post it when I do.

Radiator fan comparison

1.25in. version on top, 1.5in. version on the bottom

Left pump is Hi-Flow version

Note the significantly improved imeller

Super Duty Thermostat

Ask for 1992 Chevy Blazer 180 degree thermostat

Removing the radiator:

-The radiator, radiator fan shroud, cooling fan, and lower radiator hose can be a challenge to remove, especially on a 1968 or 1969 model car that have the radiators closer to the engine due to the deeper cowling on the inner fender.

1968/69 Year Model Cars:

Here's what I've found works the best for the early cars.

Drain the coolant using the bolt on the bottom tank of the radiator. But, be careful. If it won't budge, then don't worry about it. Put a catch pan under the car and it'll drain as you remove the hoses.
Spray all the hose clamps and the ends of the hoses with "Liquid Wrench" or "PB Blaster." This will get things moving once you start disassembly.
Remove the upper hose. It is usually stuck to the neck of the radiator and to the thermostat housing. If you aren't trying to save it, simply slice it length wise at each end, slip a screw driver in under the slice and peel the hose off. If you're saving the hose, slide a then screwdriver in between the end of the hose and the fitting, slide the screwdriver around to cut through the crud, then spray in some of the "Liquid Wrench" or "PB Blaster." A bit more gentle work with the screw driver and you should be able to get the hose freed up and slid off.
Remove the coolant recovery hose.
Remove the upper radiator bracket.
Reach underneath the radiator and you'll find a bolt which runs in the horizontal plain and points toward the firewall. The bolt head will be pointing toward the front of the car. Use a 1/2" dia. socket to loosen this bolt. You don't need to take it out yet as it will keep the radiator somewhat stable while you keep working.
Using 1/4" drive 5/16" socket, undo the small hex head screws that are along the radiator shroud on the sides of the radiator. 3 face the firewall and 3 face the grill. Remove the top 4 first, along with a 5th one that's next to the fan opening and faces the generator pulley.
Lift the top radiator shroud off.
Pull the radiator away from the fan and remove the 4 - 7/16" fan bolts and then remove the fan and any spacer that might be behind it. NOTE which way it was facing (see diagram above). Ribbed side of the fan hub always toward the radiator.
Remove the lower hose where it meets the water pump and the heater bypass pipe. Leave the hose on the lower radiator fitting.
Reach back under the radiator and completely remove the long horizontal bolt.
The radiator can now be removed complete wth the lower shroud and the lower hose attached.

Becareful you don't bash the fins on the radiator.......either against the fan blades or bolts, or against the lower shroud's corners or the cowl on the inner fender!!!

1970/71 Year Model Cars:

Here's what I've found works the best for the late cars.

Drain the coolant using the bolt on the bottom tank of the radiator. But, be careful. If it won't budge, then don't worry about it. Put a catch pan under the car and it'll drain as you remove the hoses.
Spray all the hose clamps and the ends of the hoses with "Liquid Wrench" or "PB Blaster." This will get things moving once you start disassembly.
Remove the upper hose. It is usually stuck to the neck of the radiator and to the thermostat housing. If you aren't trying to save it, simply slice it length wise at each end, slip a screw driver in under the slice and peel the hose off. If you're saving the hose, slide a then screwdriver in between the end of the hose and the fitting, slide the screwdriver around to cut through the crud, then spray in some of the "Liquid Wrench" or "PB Blaster." A bit more gentle work with the screw driver and you should be able to get the hose freed up and slid off.
Remove the coolant recovery hose.
Remove the upper radiator bracket.
Reach underneath the radiator and you'll find a bolt which runs in the horizontal plain and points toward the firewall. The bolt head will be pointing toward the front of the car. Use a 1/2" dia. socket to remove this bolt.
Remove the lower hose where it meets the water pump and the heater bypass pipe. Leave the hose on the lower radiator fitting.
Pull the radiator away from the fan and lift it up out of the car as an assembly with the shroud and lower hose still attached.

Becareful you don't bash the fins on the radiator.......either against the fan blades or bolts, or against the lower shroud's corners or the cowl on the inner fender!!!

I'll be adding more information, so keep checking back.