Bradster

1990 LS400..Looking to do a PS fluid flush and the tutorial says up to 7 qts needed depending on age of fluid...Synthetic runs about $7/quart so i'm asking what real world quantity is needed...should i just purchase the 7 intending to use all/most of that? How much does the entire system hold? Thanks to all!

trukn1

If you are gonna do a FULL flush, basically putting the car on a machine and having ALL of the fluid flushed completely out of the car(with the ago on car is something I don't recommend), then you will need 7-8 quarts of PS fluid. Reason I don't recommend with such as older car as yours and mine is that many peple have had problems with tranny failure shortly(maybe a few months) after completely flushing out the old fluid. What I really suggest would be a drain and fill, several times. Drain and fill will require 2 quarts every time you drain to refill. Run the car 200-300 miles and drain and fill again (total of 4 times) . Yes the old and new will mix together for awhile, but by the 4th drain, your fluid will practically be all fresh. Synthetic, IMO, on an older car is a gamble. Yes it does have benefits, however if you havent been doing it for most of the life of the car, or not know that this process has been done, tranny may not be able to handle it. Syntheticdoes have more lubricity than conventional and last a longer time, however as I stated, IMO, in an older car sometimes more lubricity in a system that as worn to the "dino" lubes is not always a good thing and MAY eventually cost you more to finx in the long run.

Do an advanced search in the LS forums and use the key words Tranny fluid and you will see avaried range of opinions on this subject that has been discussed already.

Bradster

Hi-You seem to be mixing power steering flush and tranny flush info