Can I use the “better 2011” hydroboost?

[treehan77]

Can I use the 1781036 hydroboost unit (2011 MY only 2500HD)? Supposedly this is a better unit than the others. I have seen many use it on there gmt800 Duramaxes, just wondering if anyone has done it on a Tahoe or Yukon? Sounds like you’d just have to enlarge the hole to fit. My truck (05 Yukon) already has hydroboost, but it is leaking AGAIN. Replaced it a couple years ago, I hear this is is better.

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[Alex_M]

Curious who says it's better - I've had 4 hydro boost gmt800s and never had an issue. Highest mileage is 270k and gaining. Sounds more like low quality reman units which is unfortunately. Quite common for anything reman at this point.

 

[ivin74]

I had 2 reman units leak from autozone, after the second one, I gave up and purchased a OEM unit and has not leaked in 3 years.

 

[treehan77]

Hydroboost upgrade for lly

I have done endless research and i find that most that upgrade to the lml hydroboost replace with either part number 19371361 or 178-1036. However when I look up to search the part number I come across two websites(one happens to be a vendor if I'm not mistaken) and they state part number...

www.duramaxforum.com

 

[TotesMcGoats]

Did you end up trying out the 2011 Hydroboost?

 

[treehan77]

Nope, nobody seemed to know anything about this, I haven’t ordered a replacement yet, still leaking slowly lol

 

[HansJr]

I had 2 reman units leak from autozone, after the second one, I gave up and purchased a OEM unit and has not leaked in 3 years.

Curious what OEM unit you found? Everything I find is reman or aftermarket.

 

[bgiff]

I can confirm it fit my 2001 Suburban 2500.
It was a direct bolt on, I didnt have to mod anything. It does seem to provide easier (less effort braking). I also replaced the power steering pump with a Duramax version from PSC- Also a direct bolt on (with yer old pumps mounting hardware).
While I was at ut, I replaced all the power steering pump lines with Edelman Elite series for max durability!

The 2011 dmax master cylinder is a close fit- bolts right on but the two line fittings are ever so slightly smaller/different thread. My plan is to cut my lines, install the proper fittings, re-flare the old lines and enjoy the larger bore diameter MC. (38.1mm vs 37)

If you have a gmt-800 with hydro b, this is a no-brainer. Not only does it work better, the 2011 Oem GM hydroboost is significantly cheaper than the older model ones. When i bought it it was over 100 dollars cheaper on Rock.

 

[strutaeng]

I can confirm it fit my 2001 Suburban 2500.
It was a direct bolt on, I didnt have to mod anything. It does seem to provide easier (less effort braking). I also replaced the power steering pump with a Duramax version from PSC- Also a direct bolt on (with yer old pumps mounting hardware).
While I was at ut, I replaced all the power steering pump lines with Edelman Elite series for max durability!

The 2011 dmax master cylinder is a close fit- bolts right on but the two line fittings are ever so slightly smaller/different thread. My plan is to cut my lines, install the proper fittings, re-flare the old lines and enjoy the larger bore diameter MC. (38.1mm vs 37)

If you have a gmt-800 with hydro b, this is a no-brainer. Not only does it work better, the 2011 Oem GM hydroboost is significantly cheaper than the older model ones. When i bought it it was over 100 dollars cheaper on Rock.

Nice to hear that!

My 06 suburban 2500 HB recently developed a leak. I ordered the 2011 after my budy (he did it to his 06 Duramax) mentioned it to me, and after seeing it was actually cheaper than a 06 HB replacement...

My order is somehow delayed on UPS, so it's a waiting game in the meantime.

Thanks for sharing your experience!

 

[ivin74]

Curious what OEM unit you found? Everything I find is reman or aftermarket.

I bought it from GM parts direct like 5 years ago. They are probably not available any longer. The hydroboost on my Yukon still going strong after 50k miles.

 

[Fless]

I bought it from GM parts direct like 5 years ago. They are probably not available any longer. The hydroboost on my Yukon still going strong after 50k miles.

Is this the part number you bought?

 

[mattbta]

ChatGPT planed out some steps (along with the T1xx 4 pot calipers)

Complete Parts List — “HD Hydroboost Conversion Kit”​

This list assumes you’re starting with a 2004 Tahoe (GMT800) that already has hydroboost, and you’re upgrading to a 2007–2010 2500HD (GMT900)–spec booster and master to increase assist and match the T1XX 4-piston brakes.

Core Hydraulic Components​

Component	Example Part #	Notes
Hydroboost Unit	GM 178-1033 / ACDelco 52-7356	Bosch HD hydroboost (2007–2010 Silverado 2500/3500HD)
Master Cylinder	GM 20861836 / ACDelco 18M2608	1.31 in bore, direct bolt-on to HD booster
Firewall Gasket	GM 15033968	Optional but recommended
Pedal Clevis / Pin	Reuse or adjust to match pushrod length	Pedal height fine-tune
High-Pressure Line (Pump → HB)	Custom or Russell 641381 (M16 × 1.5 O-ring → -6 AN)	Handles 1500 psi+
High-Pressure Line (HB → Steering Gear)	Custom or Russell 648060 (M18 × 1.5 → -6 AN)	1500 psi+
Low-Pressure Return (HB → Reservoir)	3/8 in power-steering return hose	Use clamps
Return Y-/T-Fitting	Dorman 800-640 or similar	Merge HB + steering returns
Power-Steering Pump (HD spec)	PSC SP1200-SAG / Cardone 20-6244F	2.7 GPM @ 1600 psi recommended
Fluid Cooler (optional)	Derale 13220 / Tru-Cool LPD4739	Inline cooler on steering return
Reservoir (dual return)	PSC SR146	Optional upgrade if eliminating T-fitting
PS Fluid	GM P/N 89021184 (Synthetic PS Fluid)	Do not use ATF
Brake Fluid	DOT 4 Low Viscosity (Valvoline or ACDelco)	Best for ABS bleed

---

Adapters / Fittings Summary​

Connection	Thread / Type	Adapter
Pump → HB feed	M16 × 1.5 O-ring	to -6 AN male
HB out → Steering	M18 × 1.5 O-ring	to -6 AN male
Steering gear return	3/8 barb	Hose clamp
HB return	3/8 barb	Hose clamp
Return merge	3/8 Y / T fitting	Smooth, no sharp turns

---

Fasteners & Hardware​

• (4) M10 × 1.5 flange nuts for hydroboost firewall studs
• (2) M10 × 1.5 bolts for master → booster
• (4) New copper crush washers (banjos)
• Blue Loctite 242
• Zip-ties / P-clamps for line support

---

Installation Highlights​

1. Bolt HD hydroboost to firewall using gasket.
2. Install HD master cylinder; reconnect lines (may need gentle re-bend).
3. Plumb lines per ASCII schematic from earlier (Pump → HB → Steering → Return).
4. Check pedal height — pushrod free-play ≈ 0.010–0.020 in.
5. Fill reservoir and proceed to bleeding sequence.

---

Bleeding Procedure — Power Steering / Hydroboost​

Goal: purge air from both assist circuits before touching the brake side.

1. Fill PS reservoir with fresh GM fluid.
2. Engine off: cycle steering lock-to-lock slowly 10–15×.
3. Crack HB return fitting slightly; cycle again until fluid (no bubbles) appears.
4. Tighten return, refill reservoir.
5. Start engine for 5 sec, shut off, top up.
6. Start engine, idle, and cycle steering gently lock-to-lock.
7. Repeat until fluid stays clear, no foaming, and assist feels smooth.
8. Check for leaks at all O-rings and flare seats.

---

Bleeding Brakes with ABS (Using Tech 2)​

You can now use the Tech 2 “Automated Bleed” to purge the ABS modulator completely.

Step 1 — Bench Bleed Master Cylinder​

Clamp master in vise, fill, and use bleed kit to push air out until no bubbles.
Install on truck immediately; plug ports to prevent re-entry of air.

Step 2 — Manual Pre-Bleed​

1. Fill reservoir with fresh DOT 4.
2. Have helper pump pedal slowly 3–4×, hold down.
3. Crack bleeder starting from RR → LR → RF → LF.
4. Repeat until clear fluid at each corner.

Step 3 — Tech 2 ABS Automated Bleed​

1. Connect Tech 2.
2. Navigate:
   
   Diagnostics → Model Year 2004 → Light Truck → C/K Utility → Powertrain → 5.3L → Chassis → ABS/TCS → Function Tests → Automated Bleed
3. Follow prompts: pump pedal, open bleeders when instructed.
4. The Tech 2 will cycle ABS solenoids and motor to purge the modulator.
5. Keep reservoir full throughout — if it runs dry, start over.
6. Once complete, perform another manual bleed (RR → LR → RF → LF).

Step 4 — Final Checks​

• Firm pedal after 2–3 pumps.
• No hiss / sponge.
• ABS activation test at low speed — should pulse normally.
• Recheck PS reservoir; top if low (the HB shares fluid).

---

Post-Install Checklist​

Task	Target
PS fluid level	Cold = ½ in below full line
Brake fluid level	MAX line
Pedal travel	Firm after ½ in take-up
Assist response	Immediate; no lag
Steering noise	None when turned
Leaks	None under pressure

---

Tip – Pressure Testing​

If you want to measure your new boost output:

• Tee in a 0–2,000 psi gauge at the HB pressure line.
• Under hard brake + steering load, you should see ~1,700 psi peak (vs. ~1,300 stock).
  That’s how you know the HD hydroboost is doing its job.

 

[HansJr]

Parts list needs to be for a 2011. Thats the updated one IIRC. Not the 07-10.

 

[mattbta]

I'll have it redo with the updated part.

 

[ivin74]

Is this the part number you bought?

View attachment 472012

Here you go GM#19371355, this is the part I ordered.

https://www.gatewaypartsonline.com/oem-parts/gm-power-brake-booster-assembly-19371355