Parking Brake. . .

[seedsfarmmer]

Got 30000 miles on my trk now, just recently use the parking brake and found it weak, have to push the pedal all the way in for it to activate and seem weak at bestat holding the trk. Took it to the dealer and they adjusted it, or so they said. Was in the Black Hills this past week (visiting the presidents), and when I went to use it, it was weak again and had to push the pedal all the way to the floor agian. It held, but seems like way to much pedal travel or is the cable streching? How's your's work? (side note, averaged 17.8 miles/gal doing 85 miles/hr for the most part. Got as low as 16.7 m/g 100 degrees out/air on full, and going into a head wind. Got 19.1 coming down out of Rapid City. Wasn't pulling anything, but the tow/haul mode sure works good on some of those grades! :D

[Raptorrider2001]

That is the way mine feels. Have not asked the dealer about it but figured I would get the same old "that's normal" story. Hope to take it in next week for some minor things and will add that to my list. :confused:

[ChevysRus]

I may be totally wrong, but I think the "teeth" in the brake ratchet are closer together and there are more 'teeth". This means less effort to push the E-brake and engage it. Kind of like 'Low Gear". I think they did this on most of the new cars thinking about the lady drivers, well OK older lady drivers (don't want to offend any of the younger women out there who could plant a quick strong foot in a sensite area as proof of their ablity to pump a silly E-brake).

One way to test it of course is to lock the brake with a slow and easy stroke, then put the truck in gear forward or reverse and step on the gas a little. It should hold, if not it needs adjusting.

If it holds then just go on enjoying the truck and don't worry about it.

best regards,

[seedsfarmmer]

Ya, thats how I discovered the no park brake holding power, I was parked on a incline and engaged the brake and it wouldn't hold the trk with the trany in neutral (I hate to leave tension on the transmission). Dealer adjusted and next time I wanted to use it was 3 wks later when we were in the Black Hills, (more steaper incline parking lots), and it was only slighly better. I don't really care how hard or soft, or how far I'd have to mash the pedal down, it needs to hold the trk when the trany is in neutral when I do. :eek:

[Raptorrider2001]

Mine does not have any rachet feel nor can I hear anything like a rachet sound. :confused:

[JimWilson]

Same here; no ratchet sound, and the pedal goes down real close to the floor.

[DmaxMaverick]

Late model GM's (All that I have seen, but I haven't seen 'em all) P-brakes use a friction type brake (like a sprag) on the pedal linkage, not a ratchet like on the older models. There should be no ratchet or clicking noise when you step on it. If it clicks, get it fixed.

Also, I have noticed on my HD that the pedal seems "soft". The brake has always worked very well. I think the "gear reduction" theory is probably right on. I can force my pedal nearly to the floor, but it will hold my truck and 12K 5'er on a 6% grade at about 2/3, for reference.

Also, the new HD's and 3500's with rear disc brakes, have a seperate drum brake for the P-brake, independent of the disc. Any adjustments you make should have no effect on the normal brakes (and vice versa). There was an issue back when the 01's were new. Some P-brakes were making dragging noises and sticking. The dealer's remedy was to back off the adjustment. This may have been to extreme to relieve the whining (customer's), which would require more pedal for sufficient friction.

BTW:
I had to move the P-brake cable to accomodate my larger tires. The cable now makes a much sharper bend to clear the wheel well. After the change, I didn't notice any change to the way the pedal/brakes worked. When I did this, I took into account that the cable might have more friction in it, but I didn't notice it. Still works smooth like new.

Cheers

[YZF1R]

I'll dito DmaxMaverick. It's very easy to push in but doesn't take much and holds well. I always park by shifting to neutral, foot off of service brakes, and apply the parking brake steadily until it holds, then shift to park. I don't care for my truck hanging on the trans.

Steve

[conradv]

I haven't looked into it, but have there been studies done on the effects over time of parking in neutral vs parking in park, especially with a technological marvel like the Allison?

[YZF1R]

conradv: If you are refering to my post above yours, I do put it in park after the e-brake has held it in neutral.

Steve

[ 08-21-2002: Message edited by: YZF1R ]</p>

[conradv]

Ah...

[DMAXDiva]

So what about the heavy-duty park pawl on the Allison? I've read that it will hold the full weight of the truck, but If I'm parking on a grade (unloaded), is it sufficient to hold the truck if my parking brake fails?

[YZF1R]

conradv: On a side note, I don't believe heavy duty automatics have a "park" position. When our trans. was developed, a park paw was added to it for use in our pickups. I think I read this at the Allison site.

Come to think of it, has anyone had any experience with the Allison 1000 in a school bus or anything? I think Hoot mentioned driving a six wheeler rental moving van with the Allison 1000. Did it or any other application other than our trucks have a "park" position?

Steve

[ 08-21-2002: Message edited by: YZF1R ]</p>

[Kennedy]

From what I understand we are not tied DIRECTLY to the park brake via the cable like the older trucks were. There is a spring involved to maintain/limit tension applied.

Feels goofy and cheesy, but it DOES work. It has also been suggested that one should occasionally "drag" the park brake for a short distance at a slow spedd to keep excessive rust from forming on the braking surface.

The park brake is actually a seperate drum style brake totally unrelated to the rear caliper.

[dcpdave]

the parking brake on the silverado is called a "low effort park brake apply system". the reason for this system is so that all operators can easily apply the brake. the brake is a "drum in hat" design, which means it has brake shoes attached to the backing plate, the shoes brake against the inside "drum" of the rotor. the following description is from the g.m. manual...Park brake apply input force is received by the park brake pedal assembly being depressed, transferred and evenly distributed, through the park brake cables and the park brake cable equalizer, to the left and right park brake apply levers. The park brake apply levers multiply and transfer the apply input force to the park brake actuators which expand the park brake shoe toward the friction surface of the drum-in-hat portion of the rear brake rotor in order to prevent the rotation of the rear tire and wheel assemblies. The park brake release handle assembly releases an applied park brake system when it is pulled reward.... g.m. started using this design in the 2001 models.

hope this helps,

[seedsfarmmer]

Ok, now I'm loosing my patients, and becomming frustrated . Took the trk to dealer (who is great and he and his staff take care of me), but can't seem to get my P-brake to hold. The mechanic adjusted the P-brake at the drum to the point of just about wheel drag. I was right there observing his adjustments. Tech took it to parking lot and tested (I wasn't with), brought trk around and said all was taken care of. I thanked him and took off. I went and checked on one of my fields and applyed the p-brake on a steaper field incline and it didn't hold the trk w/allison in nurtural. I think I understand how the system is supposed to work, but what should I suggest to the tech to make the p-brake hold the trk? TIA :confused: :confused: :confused: :mad: :mad:

[dcpdave]

seedsfarmmer,
ask your dealer to replace the parking brake shoes, and "sand" the drum portion of the rotor.
we had a simular problem on one truck, and had to do this to cure it.
hope this helps,