K5 Blazer Forums  
Home of the 1969-91 K5 Blazer/Jimmy including GM Trucks and Suburbans.  
Go Back   CK5 Forums > Technical Discussion > 73-91 K5/Suburban/Truck

Remove these ads.

Reply
 
Thread Tools Display Modes
Old 05-21-2003, 10:23 AM   #1
fredekr
Registered User
 
Join Date: Jul 2002
Location: Colorado Springs, CO
Posts: 92

i Trader: (0 )

How does the drum brake self adjuster work?

I took apart my rear brakes last weekend because of the following symptoms:
1. The right rear likes to lock up when the vehicle is cold.
2. It pulls to right under heavy braking.

Front pads and rotors were replaced very recently.

Here's what I found:
1. Left rear wheel cynlider seal were destroyed. Cobwebs in drum... maybe that one doesn't see much action?
2. Small axle seal leak on right rear.
3. Self adjuster on right rear contacts star wheel

It's #3 that I am wondering about. On the left side the adjuster lever doesn't rest against the star wheel, on the right side it does. What should it be like?

Here's a picture of the right side:


Do I need to replace the adjuster or shoes or what? What's it supposed to be like?

thanks,
Kevin
fredekr is offline   Reply With Quote
Sponsored Links



Remove these ads.
Old 05-21-2003, 10:51 AM   #2
gumneck
Registered User
 
Join Date: Feb 2003
Location: VA
Posts: 89

i Trader: (0 )

Re: How does the drum brake self adjuster work?

Kevin,
On the right side, are all the springs fitting in the right holes like they should. If not that maybe why adjuster is resting on it. I can't remember if its supposed to be on it full time or not. I think it is. I've been working on my rearend & have replaced the axle seals so my rear tires are off. I'll check mine after work today and get back to you on what mine looks like in case no one replies before that.

Also, you should have light friction b/n shoes and drum. You might put the drum back on and see if you can turn it hearing only light rubbing and it shouldn't be hard to turn the drum. If it is adjust the wheel so shoes kick out a little less.
Tom
1991 blzr getting new valvoline 80w90 in the rear tonight!
gumneck is offline   Reply With Quote
Old 05-21-2003, 07:07 PM   #3
79Jimmy
Registered User
 
Join Date: May 2000
Location: Richmond BC, Canada
Posts: 214

i Trader: (0 )

Re: How does the drum brake self adjuster work?

Yes, that lever should be resting on the star wheel. This is how the rear brakes are kept in adjustment, when it works. [img]/forums/images/graemlins/smirk.gif[/img] Every time you use your parking brake that lever is forced downward against the star wheel which is theaded left or right depending on which side of the truck it is on. As the lever comes down it catches on the wheel, unscrewing it and thus extending it which in turn pushes the brake shoes apart and against the drum. If the shoes are already adjusted properly against the drum the lever just skips over the star. Over the years the lever and star can wear out, become rounded, and cease to adjust properly. Hope that helps.

James
79Jimmy is offline   Reply With Quote
Old 05-21-2003, 07:52 PM   #4
HarryH3
Registered User
 
Join Date: May 2000
Location: Georgetown, TX
Posts: 10,371

i Trader: (0 )

Article Contributor
Re: How does the drum brake self adjuster work?

Check to see if that spring just behind the lever is installed backwards on the side where the lever isn't touching the star wheel. On some drum brake setups that will have the spring pushing the lever away from the star wheel. [img]/forums/images/graemlins/frown.gif[/img]

The grabbiness is due to lube and/or brake fluid on the shoes. Fix the leaks, replace the shoes, and clean everything really well with brake cleaner. [img]/forums/images/graemlins/eek.gif[/img] Then your back brakes should work just fine.
HarryH3 is offline   Reply With Quote
Old 05-21-2003, 10:28 PM   #5
fredekr
Registered User
 
Join Date: Jul 2002
Location: Colorado Springs, CO
Posts: 92

i Trader: (0 )

Re: How does the drum brake self adjuster work?

Thanks to everyone for their replies!

[ QUOTE ]
Check to see if that spring just behind the lever is installed backwards on the side where the lever isn't touching the star wheel. On some drum brake setups that will have the spring pushing the lever away from the star wheel.

[/ QUOTE ]

Which spring: the tension spring that pulls the shoes together and runs parallel to the adjuster screw, or small the compression spring that pushes that adjuster away from the shoe? Or the hold down spring that the adjuster pivots on? I think all three are installed correctly but I'll double check and see what I can see.

[ QUOTE ]
The grabbiness is due to lube and/or brake fluid on the shoes.

[/ QUOTE ]

Yes, I know that's part or all of the pulling problem and will fix it as suggested ... once I finish some other projects [img]/forums/images/graemlins/tongue.gif[/img]

thanks!
Kevin
fredekr is offline   Reply With Quote
Old 05-21-2003, 10:31 PM   #6
fredekr
Registered User
 
Join Date: Jul 2002
Location: Colorado Springs, CO
Posts: 92

i Trader: (0 )

Re: How does the drum brake self adjuster work?

[ QUOTE ]
Every time you use your parking brake that lever is forced downward against the star wheel which is theaded left or right depending on which side of the truck it is on.


[/ QUOTE ]

I thought I had read about them adjusting when applied in reverse, but this makes more sense...

thanks,
Kevin
fredekr is offline   Reply With Quote
Old 05-21-2003, 10:40 PM   #7
HarryH3
Registered User
 
Join Date: May 2000
Location: Georgetown, TX
Posts: 10,371

i Trader: (0 )

Article Contributor
Re: How does the drum brake self adjuster work?

[ QUOTE ]
Which spring: the tension spring that pulls the shoes together and runs parallel to the adjuster screw, or small the compression spring that pushes that adjuster away from the shoe? Or the hold down spring that the adjuster pivots on?

[/ QUOTE ]
That biga$$ tension spring that pulls the shoes together. [img]/forums/images/graemlins/cool.gif[/img]
HarryH3 is offline   Reply With Quote
Old 05-22-2003, 11:29 AM   #8
BrianDamage
Registered User
 
Join Date: May 2001
Location: Alabama
Posts: 756

i Trader: (0 )

Re: How does the drum brake self adjuster work?

[ QUOTE ]
[ QUOTE ]
Every time you use your parking brake that lever is forced downward against the star wheel which is theaded left or right depending on which side of the truck it is on.


[/ QUOTE ]

I thought I had read about them adjusting when applied in reverse, but this makes more sense...

thanks,
Kevin

[/ QUOTE ]


I don't know where he's getting that parking brake thing. That's the first time I've heard that one.

quote from the Hayne's manuel:

"....If the brake pedal goes to the floor, further adjustment is required. If the brake pedal is low, back the vehicle up, making repeated stops, to actuate the self-adjustors, which work only when the vehicle is in reverse. Test the brakes for proper operation before driving in traffic."

BrianDamage is offline   Reply With Quote
Old 05-22-2003, 02:29 PM   #9
79Jimmy
Registered User
 
Join Date: May 2000
Location: Richmond BC, Canada
Posts: 214

i Trader: (0 )

Re: How does the drum brake self adjuster work?

I stand corrected. Thanks for the info [img]/forums/images/graemlins/thumb.gif[/img]

James
79Jimmy is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 12:01 AM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.