Brake pedal needs manually reset after depressing

[SirRobyn0]

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]

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]

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]

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.

 

[WesN]

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]

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]

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

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

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?

 

[84K30]

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]

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]

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]

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]

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]

New dad, congrats! The real fun begins with grandchildren!

 

[84K30]

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]

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

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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 *********)

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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

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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)