2003 2WD Astro moaning sound while braking, PS pump?

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den458
I am merely driving my van
I am merely driving my van
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2003 2WD Astro moaning sound while braking, PS pump?

Post by den458 »

Question about 2003 2WD Astro possible power steering pump moan or groan sounds while braking:

ONLY as I gently apply brakes and speed decreases to about 8 mph, I hear a moaning sound in the engine compartment that remains almost until the van comes to a complete stop. The moan will continue as long as the van remains moving about 3-5 mph and brakes remain gently applied. Moan stops as van completely stops. The brake rotors and pads appear fine. Problem definitely NOT a grinding, metal on metal sound. Is it the power steering pump for sure? Is pump replacement the only solution?

Background: Bought 5 years ago with 70K miles, van now has 142K miles, has been reliable, would like to extend useful life. Moaning sound is a nuisance I'd like to resolve. Moaning sound is NOT new, I've noticed it for quite a while, I've just tolerated the moan to this point, should have investigated it sooner, but van has always stopped fine. Would much appreciate any insight into problem prior to taking van for diagnosis at GM dealer. Hope this posted in right category, thanks in advance.
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MountainManJoe
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Re: 2003 2WD Astro moaning sound while braking, PS pump?

Post by MountainManJoe »

Welcome. Does the sound change if you turn the wheel left and right?

LiftedAWDAstro
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Re: 2003 2WD Astro moaning sound while braking, PS pump?

Post by LiftedAWDAstro »

Pull the ABS fuse and run without ABS to see if it goes away. Might be a dirty front wheel speed sensor.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
den458
I am merely driving my van
I am merely driving my van
Posts: 2
Joined: Fri Jun 01, 2012 7:10 am

Re: 2003 2WD Astro moaning sound while braking, PS pump?

Post by den458 »

Thanks for replies. All steering & brake fluids are fine.

As suggested, I just pulled the 60A ABS fuse under the hood, took it for a test-drive, & the moan disappeared, brakes sound perfectly normal & quiet while braking, beginning thru full stop. The ABS dash lamp is now lit with fuse pulled. The moaning sound while braking my 2003 2wd Astro is ABS related.

I recently rode in a friends' GM pickup truck of about the same age, his brakes made a similar moan. I told him mine has a similar moan. He said the dealership said his truck had a dirty ABS sensor, replaceable &/or potentially cleanable. He declined both options as expensive... he just ignores the brake moan.

I re-installed the ABS fuse (I know I could leave it out). Now that I know its ABS related, any ideas from the forum on how I might isolate it to a sensor & process to clean it?

LiftedAWDAstro
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Re: 2003 2WD Astro moaning sound while braking, PS pump?

Post by LiftedAWDAstro »

It will be one of the front 2 sensors. You can remove the sensor out of the hub assembly and clean the dirt away but most likely you will be replacing one of the hub bearings as it is starting to fail. You'll have to follow the wire to the hub and see what it takes to remove it. They usually have a small retainer bolt and are o-ring sealed into the hole. Be very careful to not damage the sensor.

In the mean time, I would remove the ABS fuse and run it without ABS until you fix it. At some point you will want to stop fast and the ABS will be kicking in making stopping difficult or impossible.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

astroturf
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Re: 2003 2WD Astro moaning sound while braking, PS pump?

Post by astroturf »

Here is a tsb which covers the cleaning of the sensor area.

http://ww2.justanswer.com/uploads/PENTI ... _tahoe.pdf

It will keep you from farting around in the dark.

Hope it helps, Jim
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