In truth, this is a video about how to replace and bleed a master cylinder on a C1500, 1990 5.7L to be specific. However, I do have information on how you can solve a spongy brake pedal on one of these trucks by replacing the master cylinder and booster with parts from a later model truck.
Here are those part #’s
Master Cylinder: M390259
Booster: 5471046
Direct Links
Master Cylinder: https://www.amazon.com/Dorman-M390259-Brake-Master-Cylinder/dp/B001PYRLAM
Booster: https://www.oreillyauto.com/detail/brakebest-brakes-4474/brake-systems-16456/brake-hydraulics-16513/power-brake-booster-11301/power-brake-booster/5471046/4567555
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Camera: Derek Sims & Eric Cook
Discussion about this video: https://www.ericthecarguy.com/kunena/18-The-EricTheCarGuy-Video-Forum/69816-how-to-fix-a-spongy-brake-pedal-chevy-truck
Links
Line Wrenches: https://store.snapon.com/Open-End-and-Flare-Nut-mm-5pc-6-Point-Open-End-Flare-Nut-Metric-Wrench-Set-10-mm-14-mm–P630777.aspx
Plastic Plugs: https://parts.cat.com/en/catcorp/shop-supplies/caps-and-plugs/9U-7075
Silicone Spray: https://www.wd40specialist.com/products/silicone-lubricant/
Zep Brake Cleaner: http://www.drillspot.com/products/643623/zep_r18935_brake_wash_solution
Zep Brake Cleaner Sprayer: http://www.apmengineparts.com/829801.html
Master Cylinder Bleeding Tool: https://www.jbtoolsales.com/thexton-804-master-cylinder-bleeder-kit#oid=1002_1
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5.7L Water Pump Replacement (Part 1): https://www.youtube.com/watch?v=trhJrE1I3kk&t=18s
5.7L Water Pump Replacement (Part 2): https://www.youtube.com/watch?v=6kElUsAPkoA
How To Bleed Brakes: https://www.youtube.com/watch?v=V5O_pbC8R2E&t=6s
How To Replace a Wheel Cylinder: https://www.youtube.com/watch?v=p8k5GfTpZr4
1999 Chevy Tahoe Rear Brake Shoe Replacement (Part 1): https://www.youtube.com/watch?v=195JUby2Uy4
1999 Chevy Tahoe Rear Brake Shoe Replacement (Part 2): https://www.youtube.com/watch?v=D6I9HtUC_hM
How To Deal With a Spongy Brake Pedal (Honda): https://www.youtube.com/watch?v=KIQIBLGoZJ4&t=1s
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Well there's your problem… it's a Chevy lol
i've had to do more master cylinders on chevy trucks than i even want to think about…..a little trick i have done to get the air out of the lines is,i will take a front and rear wheel off,and have someone push the caliper piston back in with a c clamp while i loosen the line at the master cylinder. i do bench bleed the master with brass fitings and clear tubing before hand.
Misleading thumbnail.
I’ve found that most times you can bleed your old master cylinder and it’s fixed. Do that before buying a new one.
I did the master cylinder still the pádel go to the floor!
Upgrade to a hydro-boost. It is much better !!!
I couldn't get air out the system for months.So I put the heavy duty master cylinder.Bench bled and bleed all four wheels.Brakes work perfect.
I fixed my soft pedal by changing the cap on the master cylinder reservoir, I do have a question, you pump the brake pedal to bleed the brakes, but its difficult on a power brake system,when the cars not running theres no pressure??? a mechanic friend told me put small clear hoses on all four bleeder screws and open them all then and have them drain in a pan or jar filled with some brake fluid and let gravity do the rest eventually the air will push out,sort of like when you siphon
Very good thanks
my 2004 GMC SLT 1500 is Spongy also and has been for years… Thanks for the video
I had the same problem. Fixed by pressure bleeding. Normal bleeding did not work.
Am haveing the problem how do u
I solved the problem
Man, I miss watching his videos. Down to earth, honest mechanic and person.
Y not go with a new master cyl. with reservoir already installed?
The whole time he was pumping the brake I could hear it was your brake booster.
Bleeding master at the master pushes air into the lines
I replaced two rear wheel cylinders on 91 Ford Ranger. I've tried all the bleeding tricks and I still have a spongy brake. Solution? Take it to a brake shop.
sell it and buy a Dodge.
The combative hallway bailly attack because bottom basically undress apud a slow cartoon. abashed, shaky size
Great vedeo i do exactly on my 95suburban but the brake pedal loose pressure!! When I press the brake pedal he going to end and not keep pressure!! And not leaking brake fluid anywhere! I tried many times and not have a normal pressure on brake pedal!! Anybody knows what's wrong 😕 thanks fellas
Is it weird that I can smell brake fluid while watching this?
I have an 06. And what was causing my sponginess was that i had the front and rear ports criss crossed between the abs module and the master cylinder. Took forever to figure that one out.
Excellent video. The easy way to fix a brake issue. Easy step by step instructions on this to keep from having issues later with the brakes , great video. Thanks
hi erik i have a 79 camaro and when i press the break pedal it sounds like air is leaking n ita harder to break the more i drive do i have to replace the whole booster?ðŸ™ÂÂ
will the parts in the description work in a 05 Silverado? Asking anyone
I use a pressure bleeder, needing 2 people to bleed brakes is a waste of time to slow and doesn't always get all the air out, Time is money. Why any professional tech wouldn't invest in a pressure bleeder is beyond me
Great video thanks for posting .
Hi Eric O without bench bleeding the brakes can't work or bc I have been bleeding same brake the whole day but still the brake is not working please for your advice thanks
Nice video thanks very much well understood
I replaced my master cyl. In my 01 1500 express adj. Rears bleed all the lines, replaced both calipers with ceramic pads, still have soft pedal, i cant figure out why?
Eric
Just remove the sponge
Flush your system,new brake fluid,old brake fluid will contribute to spungy peddle.
I'm 42 yrs old. Have done all my own work forever and never had to replace a master cylinder.
Great process. Nice explanations. Thanks!
I took the rear abs out of the equation in 3 of these trucks I've had. Good firm pedal after that
I'm watching this video because I have bled all four calipers twice but still I'm getting a spongy feel when the engine is running. Pedal is solid after a few pumps when engine is off though. Where could the problem be?
Just did the NBS master cylinder swap…was easy to do and about to bleed it one more time and then fire it up and see what it does 😎
Just crush it
I guess everybody here forgot about the proportioning valve.
So it didn't work??? I watched the whole damn thing and it didn't work??? Misleading title. Should have said "Trying to fix spongy break pedal…FAIL"
I was taught to put short brake lines from the ports back into the reservoir and pump till the bubbles stop. It's always worked for without most of the mess.
I'm honestly curious what your feelings are about vacuum booster vs hydroboost? My current truck is hydroboost and it's the first ever I owned. I like it but that's subjective at best.
i ordered the booster you recommend, but it doesnt match the old booster one bit off my 1989 suburban. Now what?
I have a 99 Tahoe and just cannot get a brake pedal that doesn't go 3/4 to the floor
Great job master.
I'm sure you get this all the time but.
What's the go with the yellow tint on the safety glasses?