To Drain systems or fill

[Beachbums]

I am helping a friend with a 4th gen 4 runner, 2007 v-6 he picked up for his kid,160k on the clock that has been poorly maintained. Some repairable frame rot.

I don't believe, with the conversation I had with the people settling the estate, that the cooling system has ever been flushed. Power steering pump fluid looks nasty.

The rear brakes were put together without the springs and wear indicators, the caliper pins seized. Lines full of air. Pure genius. Did calipers and pads, rotors were within spec. Differential and transfer case levels good. When greasing the prop shafts and u joints it seemed to take way too many pumps to fill. One half shaft weeping.

I am of a mind to fill, and keep my fingers crossed. It will be used as an around town beater. I can see that flushing out c**p could lead to tales of woe.

 

[CayRunner]

I'm interested in what the recommendations are here as well. Similar situation, I purchased an '03 with 150k miles. Would be keen to flush every system as well if it's recommended.

I've already run into the 4LO seizing problem, ECU communication issue, and ABS system failure.

Good luck with the rebuild and I look forward to seeing your findings!

 

[fourwd1]

For a used '03 with 150K you may not know it's maintenance history, in which case draining/flushing/replacing various fluids would be very important.

Since the OP was discussing cooling, brakes and PS systems, those would be a good place to start. A complete drain + flush will help a lot. The different fluids not only do their main job, but also act as lubrication for those systems, and wear out over time and use.

There are plenty of threads and How-To's on this site if you search.

Then later you could move on to transmission, transfer case, and diffs.

 

[fourwd1]

And welcome to T4R.org both of you. :thumb3:

 

[Buckaroo]

I am helping a friend with a 4th gen 4 runner, 2007 v-6 he picked up for his kid,160k on the clock that has been poorly maintained. Some repairable frame rot.

I don't believe, with the conversation I had with the people settling the estate, that the cooling system has ever been flushed. Power steering pump fluid looks nasty.

The rear brakes were put together without the springs and wear indicators, the caliper pins seized. Lines full of air. Pure genius. Did calipers and pads, rotors were within spec. Differential and transfer case levels good. When greasing the prop shafts and u joints it seemed to take way too many pumps to fill. One half shaft weeping.

I am of a mind to fill, and keep my fingers crossed. It will be used as an around town beater. I can see that flushing out c**p could lead to tales of woe.

The drain & fill rather than flush recommendation is really for the transmission. If it hasn't been changed forever, you don't even want to drain it....just let it be. I would think at 160,000 miles it would be ok to drain and fill. You could save the old fluid and if the trans starts slipping after the fluid change, put it back in but I don't think that will be necessary.

The engine cooling system would be fine with a flush but I typically just do a drain & fill on that and then repeat it every 30,000 miles thereafter. Also replace the thermostat & radiator cap.

Flush for brake fluid also appropriate.

Also would want to drain & fill the front diff, back diff and transfer case. No question of flushing there. Always make sure you can get the fill plug out before opening the drain plug.

Good Luck!

 

[Beachbums]

This problem may have mushroomed. It was down 750ml of coolant, and after refreshing, triggered a CEL. It did this before and the code was about catalytic converter inefficiency I think. Antifreeze in cats will do that. This weekend pressure check the cooling system and put a camera into the combustion chamber to look for droplets.
Oh joy.