Brake pedal needs manually reset after depressing

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,698
Reaction score
11,151
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
Did it do it before you replaced the master?

That's exactly what I was thinking. I think if it didn't do it before he replaced the hydroboost unit, it might just be a bad unit.

Uh... with that knowledge..

have you looked at your pedal return spring?

its a spring that returns your pedal

I would check that. Also check the pivot on the pedal. I'm not insinuating that your truck is rusty in this next statement, and it is not specific to GM vehicles with hydroboost rather it is across the board with all old vehicles, but we see it happen more in trucks and vans. Those pivot points can get rusty and stiff and it can be a real pain to get the bolt out and get it cleaned up. The best test is to disconnect the return spring, and link rod. The pedal should flop to the floor with it's own weight, if you have to push on it at all it's to stiff and may bind. Remove the big pivot bolt and pedal, clean everything up until it's clean and lube with silicone grease if you have it, if not just use regular grease.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
perhaps all rubber hose sections on the truck collapse on return and your spring is too weak to overcome it. this is a hard to think of scenario because its unlikely it would be able to get that bad before being fixed already and i feel it would have a hard time moving even if you moved the pedal
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
That's exactly what I was thinking. I think if it didn't do it before he replaced the hydroboost unit, it might just be a bad unit.



I would check that. Also check the pivot on the pedal. I'm not insinuating that your truck is rusty in this next statement, and it is not specific to GM vehicles with hydroboost rather it is across the board with all old vehicles, but we see it happen more in trucks and vans. Those pivot points can get rusty and stiff and it can be a real pain to get the bolt out and get it cleaned up. The best test is to disconnect the return spring, and link rod. The pedal should flop to the floor with it's own weight, if you have to push on it at all it's to stiff and may bind. Remove the big pivot bolt and pedal, clean everything up until it's clean and lube with silicone grease if you have it, if not just use regular grease.
silicone because not too bad for dust collection, water proof, and rather tacky? also rather unreactive
 

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
156
Reaction score
64
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
Pedal did not stick prior to replacing hydroboost unit. Just confirmed that the brake pedal return spring is in place. I guess I was able to replace the hydroboost without removing it, which would explain why I didn't recall seeing it.

Perhaps a useful piece of information is that the pedal does "reset" when the truck is not running. When the truck is running, depressing the brake pedal results in an audible groan which I believe is coming from the power steering pump. Also, the issue seems to be less prominent when the truck is not yet warmed up.

Truck is originally from South Eastern New Mexico so nothing in the way of rust beyond discoloration on the frame where it isn't painted.

Everything rubber on the truck is questionable though. I did put on two new PS pressure hoses when I changed the hydroboost unit. Also changed the fluid (AcDelco) and bled the system at that time.
 
Last edited:

WesN

Full Access Member
Joined
Feb 15, 2018
Posts
209
Reaction score
565
Location
Edmonton Alberta Canada
First Name
Wes
Truck Year
1981
Truck Model
C1500
Engine Size
350
I had my brake pedal doing a funny thing kind of like yours after I pushed on it and released it would stay down a little for a second and then would make a small pop noise and jump up to normal position. Took a while to find it but it ended up being the vacuum dump switch for my cruise control. It would stick for a second and then snap closed. I took it apart and cleaned and lubed it and now no more issues with my brake pedal. Not sure if this is the same but.........gremlins in an old truck.
 

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,698
Reaction score
11,151
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
silicone because not too bad for dust collection, water proof, and rather tacky? also rather unreactive

Basically you have my thinking down. For me regular grease goes in zerk fittings and wheel bearings and that's about it. Anything I disassemble and want to grease gets silicone grease. There are other products on the market now, but a lot of brake lube made for lubing caliper slides and backing plate pivot points on drums, the clear / light tan colored brake lube is made from silicone. I was impressed with how well it would work in those wet dusty environments. It also will not hurt rubber unlike regular grease. So I have been using silicone grease for a lot of stuff for a long time and for me at least it works really well.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
9,735
Reaction score
9,532
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
Front brakes are not overly worn. Rear brakes could be-I've never pulled the drums because the brakes had always worked and never made any strange noises of hung up. Due to the need to pull the axles, I figure I'll just changes the drums, wheel cylinders, bearings, shoes and hardware when I do get around to checking them

-Eric


o_O
What?

Also, the pedal "sticks" regardless of how far/hard I push on the pedal. It will stay depressed with even the slightest amount of pressure


:eek:
Dude!


This thread is way better since @AuroraGirl started adding pix, ahem, ahem.
Y U holding out on the 84K30 pix yo? That would be cool. Not a lot of 84k30s runnin around today, no?

Wtf? :33:
 
Last edited:

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
156
Reaction score
64
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
Rusty nail,

It is my understanding that the rear axles need to be pulled in order to remove the rear drums(14 bolt FF) For this reason, when I take things apart it will be to replace everything.

My rear brakes have not been hanging, making odd noises and my braking performance is more than adequate at this time.

In short, I'm not going to spend time checking something when its not giving me problems. I also am not in any rush to spend $500 on new drums, shoes, hardware, wheel cylinders, when the money would be better spent addressing other worn parts.

Everyone else,

The groaning noise I hear when my brake pedal is depressed with the engine running is also present at the extremes when I turn my wheels lock to lock.

-Eric
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
9,735
Reaction score
9,532
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
The groaning noise I hear when my brake pedal is depressed with the engine running is also present at the extremes when I turn my wheels lock to lock.

-Eric



I see @C10MixMaster in here, we should ask him. :) Right up his alley.
 

C10MixMaster

Full Access Member
Joined
Dec 6, 2016
Posts
756
Reaction score
1,420
Location
Kingman AZ
First Name
Ben
Truck Year
1977
Truck Model
C10 BIG10
Engine Size
ZZ4 350
The groaning noise I hear when my brake pedal is depressed with the engine running is also present at the extremes when I turn my wheels lock to lock.

-Eric



I see @C10MixMaster in here, we should ask him. :) Right up his alley.


sorry not a hydroboost expert , but sounds like a ps pump/ hydroboost issue and not a brake issue. Just my 2cents.
 

AKguy

Full Access Member
Joined
Feb 16, 2019
Posts
537
Reaction score
877
Location
Alaska
First Name
Randy
Truck Year
1981
Truck Model
K30 Crew Cab Silverado
Engine Size
460
So, when you changed the hydroboost did you retain the same plunger rod and did you measure for the correct length? When I put my new hydroboost unit in I had to trim the rod. Get ahold of the folks at powerbrakes.com, they know this stuff!
 

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
156
Reaction score
64
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
I did not retain or measure the old plunger rod.

I also cannot recall what the stamping number was on the old rod (I’m a new dad, I’m happy to make it through each day at this point). I want to say it was the same as the new one but am not 100% sure.

However, I did confirm that the rod on the new (rebuilt) unit was stamped with 71217, which is the road that @Craig 85 said I needed. He has helped me a bunch of times with various issues and has never steered me wrong.

-Eric
 

AKguy

Full Access Member
Joined
Feb 16, 2019
Posts
537
Reaction score
877
Location
Alaska
First Name
Randy
Truck Year
1981
Truck Model
K30 Crew Cab Silverado
Engine Size
460
New dad, congrats! The real fun begins with grandchildren!
 

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
156
Reaction score
64
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
Thanks. I keep hearing that, seems like there is a joke hidden somewhere in that statement? Hopefully I have at least 25 years years before that happens.

I'll swap out the power steering pump. If that doesn't resolve the issue, I'll pull the hydroboost I just installed and swap it out too.

-Eric
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Basically you have my thinking down. For me regular grease goes in zerk fittings and wheel bearings and that's about it. Anything I disassemble and want to grease gets silicone grease. There are other products on the market now, but a lot of brake lube made for lubing caliper slides and backing plate pivot points on drums, the clear / light tan colored brake lube is made from silicone. I was impressed with how well it would work in those wet dusty environments. It also will not hurt rubber unlike regular grease. So I have been using silicone grease for a lot of stuff for a long time and for me at least it works really well.
i use that brake parts ceramic by permatex. That **** is tacky in both style and function.
I literally hosed my brake caliper aiming at the slides and it didnt remove on a jet function of my water hose any of the stuff. Sticks to everything. but it doesnt collect dust very much. And whatever dust it collects i think it kinda absorbs it internally and takes a lot of time to become saturated like if you had playdo and dirt slowly added to it. just meshes in. last stuff i put on my passenger front of my car and I do a LOT of heavy braking. I get those puppies cooking
You must be registered for see images attach

like this is what the pads looked like. pretty glazed right.
So Im pretty much an expert on brake parts lubricant. I use that on metal parts(backing pads, slides, etc(you can see some remnant of that Grimace *********)

You must be registered for see images attach
dont be a jack ass like this guy and go and ruin the boots or the internal rubber stop bushing in the bracket because this WILL ruin the rubber parts. I use 3M Silicone Paste for this job, as you probably are too. I want to try this next
You must be registered for see images attach

It says it can do the job of purple and silicone.. but im just thinking purple is best as its single function for metal-metal and another separate product can handle the rubber. i just dont see ceramic solids and petroleum distilates working with rubber that (s)well(hehe)
 

Latest posts

Forum statistics

Threads
41,856
Posts
903,621
Members
33,370
Latest member
mitchell1128
Top