05 had low PS fluid and is now groaning (1 Viewer)

[SpeedAgent]

Hey guys,
I got this 100 for my wife back in April and never baselined it as I had a lot of receipts from recent work. A few days ago the rig started making some weird noises while driving slow and also while turning in tight parking lots. It's my wife's car and she said it happened several times and she could feel it in the steering wheel and she thought she felt it in the brake pedal (vibration). I assumed it was low on PS fluid and it turned out to bel below the" low" marker, but not down to the hoses on the resevoir. I topped it off and drove it for a short trip- no noise for me, but the next day my wife said it was doing the same thing. Anyone think this sounds familiar to them? Here are some of my question;
1. Why would the fluid be low? I see no evidence of leaks.
2. Are PS leaks or issues common to a 100 or an 05?
3. Could it be that there is now air in the system? If so, how would you recommend I purge it?

Thanks for the help in advance.
chris

 

[Yotato]

Bleed it: Top off the reservoir, jack up the front wheels and and turn the steering wheel lock to lock to bleed while engine is running. Periodically check the PS fluid for low level and bubbling.

 

[SpeedAgent]

Does the cap need to be off while ddoing this?

 

[NMuzj100]

Cap on or off is fine. After filling watch it closely to be sure you don't have a leak somewhere.

I wouldn't say power steering issues are common except among those rock crawling or running oversized tires.

 

[SpeedAgent]

I'm now thinking it isn't the power steering. My wife said she heard a whiring sound as she was slowing down to a stop this morning. She also felt it in the brake pedal. I'm sure the rotors were already warped, been that way for a while, but this noise comes and goes even when the brakes aren't applied. Does this make any sense to anyone?

 

[SpeedAgent]

How to tell if the brake booster is going bad?

I think, after reading some of the search results, that my issue may be a bad brake booster, but I'm not sure. Anyway to tell? This is my wife's car that carries my kids to and from school everyday so I need to figure this out quickly.

Thanks,

Chris

 

[2000UZJ]

Tires worn funky cuasing the sound/vibration to resonate through the streering wheel?


Not sure what kind of tires you have, but my KM-2's like to make funny sounds around 15-0mph.

 

[SpeedAgent]

I don't think that's it; they are Michelins and we have had them a while. A bad tire wouodnt cause these other problems.

 

[2000UZJ]

I don't think that's it; they are Michelins and we have had them a while. A bad tire wouodnt cause these other problems.

No idea then, my PS system groans and hisses. It's full of fluid and the rack is fine. I'm sure my cause is different from yours though.

 

[SpeedAgent]

I should note that the problems/noises we are experiencing are not only when the brakes are applied.

 

[Liam]

it would help if you posted your symptoms and what year truck you have

 

[SpeedAgent]

I'm taking the LC for the day tomorrow to see if I can figure out what is going on. I was hoping to narrow it down today in case I needed to buy parts tomorrow.

 

[SpeedAgent]

Sorry, didn't want to repost same info from other post.

It is an 05 LC. My wife has had an issue with a whirring sound and also vibration in the steering wheel and brakes for the past few days. I took a look initially thinking it could just be low PS fluid. The fluid was in fact low and I topped it off and drove it and found no issues or heard strange sounds. I thought it was fixed- it was not. The sound continues and the vibrations are still there. My wife made mention today that it seemed like the vibration was almost like a skipping feeling, like the car was skipping. The issue is not cold or hot dependent as it does it before the car gets hot and then also after it has been driven for a while. My wife has also noticed it when driving through parking lots with frequent short turns. Could this be a bad CV? Brake Booster? Something else that might be a wear out part? The rig has 103k miles on it and I have not done any suspension/steering maintenance on it since we bought it in April.

Thanks,

Chris

 

[re_guderian]

Worn brake pad? I'm a little shocked to say how far down my wife let them get before saying something about them...

 

[Travis351]

Sounds like the electric brake booster to me. It is on and off all of the time, both during and after braking. Just turn the key to the on position without starting the motor and see if that's what the offending noise is.

 

[SpeedAgent]

It doesn't do it in any pattern or cycle and isn't dependent on the brakes being used, but upon reading some of the threads in the search under "whirring" I found a post about the electrib brake booster. Does anyone know how much this part is and how hard it is to replace? Anyway to actually test it before buying a new one?

*Holy hell! The brake booster parts are super expensive. I hope this is not it.

 

[2001LC]

A couple of ideas:

1) Check the brake pads, you could be hearing the early warning low pad sound.

2) Flush the PS fluid and with synthetic ATF. Mobil One synthetic ATF is readily available.

 

[Travis351]

When mine failed, the BRAKE light illuminated on the dash and brake fluid was leaking. Do you hear the noise with the key on and the engine not running?

 

[NMuzj100]

Make sure the center diff isn't activated. It'll cause some skipping and noise when turning.

 

[SpeedAgent]

I checked the brake pads and although they were new in April they aren't anymore. They are pretty low, but now alarmingly low. I've never had brake issues on other cars where the pads were this low. In fact, one time I was almost on the metal backing plate after tracking my M3 and I could barely tell. Anyway, would this cause a vibration in the brake? I'm thinking the brake pedal vibration may be low pads and the groaning may be air in the PS lines....does this sound plausible?