I recently purchased a 1990 240 sedan with low mileage. In looking over the records, I do not see that any fluid changes (coolant, transmission, differential) were ever done. Not being a mechanic, I am looking for recommends on what to do. So a few questions:

- When changing the coolant, should I get the system flushed, or *just* change the fluid?

My mechanic recommended against getting the system flushed; that it could create other problems by moving any deposits around the system and creating possible leaks in the water pump, etc.

- When changing the transmission and differential fluids, does it make sense to change to synthetic oils? Are there advantages to the synthetic oils?

My mechanic recommended against synthetic oils noting the difficulty of getting all the non-synthetic oil out, and not wanting to mix the two. He noted that they replace half the fluid each time they change the fluid since half the fluid is below the drain point.

So what to do/not do?

Thanks

 

You should just drain and refill the coolant.That is usually done every 30,000 miles.
You can change to synthetic oils will not really hurt anything.In five years of working on Volvo's never seen any problems from switching to synthetic oils.The trans fluid change is I believe like every either 40,000 or 80,000 I forget.But you should be fine with doing what you wanted to do.I just wouldn't flush the systems.

 

Tech, why wouldn't you "flush" the radiator and transmission? That is the only way to completely rid the trans and cooling system of the "old stuff". The same holds true of the braking system..................it is suppose to be flushed on an annual basis.............
reg.

 

I would fush the brake system only.You can change the trans fluid another way bye taking the return line off the radiator from the trans and install one quart then start the car and let one quart drain out then turn off and add another quart then do it again till you have done 12 quarts.That is the best way to do it.On the Volvo transmissions they don't like to be flushed.Out of all of them I have seen flushed they came back for transmission problems.Coolant stays good for a long time so draining and refilling it wont hurt for the 1/4 of a quart or so that doesn't come out it won't hurt the engine.

 

Thanks Tech! Next change to the trans I shall do and save $145.00. Incidently, I use Ate Super Blue dot 4. I then alternate it with Ate racing dot 4 which is yellow (same boiling point) and that way I know when the entire system is bled.
Reg

 

No problem anytime