GM Genuine Parts 178-1036 (19371361) Power Brake Booster Assembly

WOW! Amazing, the brakes stop my truck better than the day I drove it off the lot. Perfect fit on my 2005 GMC Sierra 3500. Recommend everyone upgrade their trucks!!! Watch You tube before attempting the change out. I did put one on a second truck. This time the transmission failed to shift. Although instead of drilling the shaft hole out 1mm, I disassembled the brake light switch and readjusted the contact,. One of three contacts in the switch, foreword most one. Now the throw is shorter and fixed the issue without drilling the hole. Just wear safety glasses as there is a spring inside the switch that may pop out and hit you in the face the first time you disassemble it. Seemed a bit overwhelming at first but, it was relatively easy once I got it apart. The brake light switch on the 2011 GM is a bit different than the 03-07 models. Very pleased with the result. I did order a second switch in case I failed, Now that extra sets in the glove box as a trophy reminder of the simple fix it was without drilling.

I installed this on my 03 sierra 2500HD. It fit perfect and the brakes feel so much more responsive than before. Like others have said, you may have to open up the hole on the shift that connects to the brake pedal. At first I did not but did in the end as I was trying to trouble shoot why my truck wouldn't come out of Park after everything was installed. Turns out I had damaged the brake switch when I was removing the 4 nuts under the dash. Be very careful with this switch and remove it fully so it does not get knocked around. Very happy with this product and would have been an easy install if I hadn't damaged the switch. Much cheaper than the direct replacement one too.

installed it 2 weeks ago on my 2003 GMC 2500 and so far so good. fits perfectly and works great

Big difference from old leaking factory one. Brake pedal is much more responsive. Bolted right up with no modification on my 2003 Silverado 1500hd. Hardest part was removing and replacing the brake pedal clip. Spent an hour trying to put the clip back on. Ending up popping off and never found again. Had to go to the dealer to replace it cause local parts store don’t carry it.

Took a long shot on this for my H2, which is not listed as a vehicle this works with. After installing the unit I spent hours head scratching and troubleshooting why my shift interlock and brake lights didn’t work—let me save you trying to solve that mystery. There’s a few reviews and several write ups about some people having to drill out the under dash rod from the new hydroboost that connects to the brake pedal. But they never explained why and I thought it had to do with the pin on the brake pedal being slightly too large for the rod to hydroboost to connect properly. Turns out you may have to drill the new HB rod about 1mm or so larger (not very much at all) in order for your brake light switch and shift interlock to work properly. I used a step bit from harbor freight and drilled out both sides of that rod by one step on the bit, like I said, not much needed. It’s really that simple. And it turns out this hydroboost unit is actually a great upgrade for better performance on your 2001-2010 GM heavy duty. This is a redesigned for 2011 unit with better performance overall.

I rarely take time to do a review on products. In this case, I feel an exception is warranted for those who my find my unique situation helpful. My old brake booster was still working, but it had started to leak power steering fluid on the top side of the wheel well and leaving a mess on my driveway. I bought this product based on internet comments and suggestions that I hoped fit my situation. The recommendations were to buy this specific unit designed for a 2011 truck as an upgrade to older trucks with a similar booster. While most were discussing diesel pickup trucks or similar, I bought this for a 2003 Chevrolet Suburban 2500 with the 8.1 Vortec engine. I've had it in for roughly a week. Other than the expected challenges with accessing the 4 nuts holding the unit to the firewall and connecting up the main rod to the brake pedal, everything fit like the old unit, and I haven't seen any issues with the brake lights. No modifications were necessary. The rod hole appears to be identical to the one I took out. I did have a challenge with the retainer clip due to limited space. My truck has the adjustable brake pedal option, and I didn't see anyone on the internet with that setup in my research. In the end, I was able to get it connected up, and everything is working great. I've noticed firmer braking as others have noted, so I agree this one feels like a valuable upgrade from what was in the truck. I hope others find this helpful.

Received item, (hydro booster) ordered through Amazon. Replaced due to leak. Installed new hydro boost with no problem. Worked great but started a new leak. Frustrated, took to mechanic. Mechanic found the new hydro booster had a leak. Had mechanic replace booster that cost over $600. Called GM AC Delco per the return policy of Amazon. GM said I had to go through RockBottomAuto to return since it was bought through them. Contacted RockBottomAuto who said item is not returnable. WTF?

It was an upgrade for the truck and it was night and day difference. Perfect booster.

perfect. fit like a glove. love oem parts