my friend just left my house after visiting on her roadtrip and made it only about 20 miles away up the mountain (i live in arizona) she and her kid hitchhiked back and we are now going back out to try and figure out the problem

here's the info I have so far, will update:


1985 toyota 4runner

going down hill, extreme grinding sound

she would stop accelerating and then it would whine loudly

but when she came out of gear all the bad sounds would stop

but then she would lose power to Steering AND brakes

but like intermittently or like flickering in and out

but she was still able to downshift and did not stall

still running, still has electric, but couldn't keep driving without the brakes.




I'm confused because AFAIK the power and brakes should be completely independent systems although I did read that maybe the ABS uses power from the steering on some models?

all tips welcome hoping to avoid a long delay and mechanic visit.

Thanks!

Wild guess, but did a brake fail, such as a pad going full metal contact, resulting in noise, erratic braking?

Seriously doubt there is any electrical assistance to steering or brakes in a 1985 vehicle. AFAIK brakes would be vacuum assisted and power steering hydraulic.

Losing ABS (if equipped) should not disable the brakes, just the ABS function.

I wish I were more familiar with this age 4runner to give you more assistance, hopefully someone more knowledgeable will chip in.

The truck has been moved to a mechanic.. we got out there and looked it over but couldn't find any external problems. I believe a rattling sound is coming from inside the motor.

not sure why a internal motor problem would cause steering/braking issues. and in an 85 the brakes arent electric so that seems odd

Brakes and steering are 2 different systems. Brakes have a vacuum power assist and the power steering has a belt driven pump. Both require the engine to be running for the power assist functions to work. Both will work without engine running but require a lot more effort to work. No ABS on an '85.

There's many internal engine problems that could make noise, but the most common would be a worn/loose timing chain slapping inside the timing chain cover. The chain should be replaced every 100-115K miles or so, has that ever been replaced?

Given the symptoms, it could be a problem with the powertrain or drivetrain. Probably, there's an issue with the transmission, differential, or even the transfer case. Also, maybe, check the transmission fluid level and condition.

Regarding the power loss to both steering and brakes, while these systems are typically independent, there could be a common issue affecting both. This be a problem with the power steering pump or a vacuum leak messing with the brake booster.

As for the rattling sound coming from inside the motor, this could mean an internal engine issue, like maybe, a worn-out bearing, piston slap, or even a damaged valve train component.