Replacing Master Cylinder (Brakes) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wakeboarddrumma · 02-11-2007, 06:07 PM

My brakes have been out for a while. So I haven't driven the truck. We called the shop we always take it to, and they said it's probably going to be the Master Cylinder. So we said ok, and then they were going to have to tow it, so we decided we'd replace it ourselves, as it couldn't be that hard.

Anyways, we went to Advanced and got a rebuilt one yesterday, and I was just wondering how hard of a job it will be? How long am i looking at for the replacement?

krue · 02-11-2007, 07:10 PM

Just follow the instructions for bench bleeding, then bleed all your brakes carefully and you should be done with an hour or maybe two or work in it.

GMCBubba · 02-11-2007, 10:19 PM

yeah, i just finished mine a couple weeks ago. and if i can do it, then truly anyone can.

GMCBubba · 02-11-2007, 10:37 PM

oh, and if you're going to the effort to bleed your brake system, you might think about replacing your old brake hoses with new ones. mine were pretty bad. granted, i just replaced everything in my brake system except the hard lines.

msgross · 02-11-2007, 10:40 PM

buy a big jar of fluid as you will need it to bleed. takes two people as well... Might pick up a 7/16 line wrench if you don't have one.

krue · 02-11-2007, 11:13 PM

Get a GOOD line wrench, don't cheap out here, you'll round off the nuts if you don't.

**CMars45000** · 02-12-2007, 12:44 AM

Quote:

Originally Posted by krue

Get a GOOD line wrench, don't cheap out here, you'll round off the nuts if you don't.

I agree...This is one of the few tools where I called the Snap-On guy..The craftsman ones didn't cut it...they sure have saved a lot of head aches...

GMCBubba · 02-12-2007, 07:40 AM

yes, rounded nuts. been there, done that. there's at least a couple good sides left to all of my nuts. but they're not as pretty as i would like.

wakeboarddrumma · 02-12-2007, 09:13 PM

Well my older brother got the cylinder mounted. Said something about taking off the valves at the wheels and how he couldn't do it. This sound familiar? He stopped, and is going to finish up when he figures it out.

msgross · 02-12-2007, 10:08 PM

If the wheel cylinders are leaking then they need replaced, maybe the valves on them are bad, you have to open them to bleed the system

krue · 02-12-2007, 10:15 PM

Here's a tip for those of us with cheap line wrenches. If there is room, clamp a pair of vice grips on the wrench to keep the ends from spreading, I figured that out in the junkyard the other day.

FarmTruk · 02-12-2007, 11:41 PM

Quote:

Originally Posted by krue

Here's a tip for those of us with cheap line wrenches. If there is room, clamp a pair of vice grips on the wrench to keep the ends from spreading, I figured that out in the junkyard the other day.

Thanks krue...that IS a good tip. Wish I'd thought of it. I've rounded off several in my past.

wakeboarddrumma · 02-12-2007, 10:54 PM

Is there a speacial tool for the front valves?

krue · 02-12-2007, 11:07 PM

If you're talking about the bleeders, just use a boxed end wrench.

krue · 02-13-2007, 08:05 AM

It just struck me the other day in the junkyard. I had a pair of vicegrips in my hand and waalaah (or however you spell it).

msgross · 02-13-2007, 08:46 AM

Here ya go....

Quote:

Originally Posted by krue

It just struck me the other day in the junkyard. I had a pair of vicegrips in my hand and waalaah (or however you spell it).

http://www.answers.com/topic/voila-1

or

http://www.answers.com/voila

JustLiveIt · 02-13-2007, 12:01 PM

I just replaced my master cylinder and all brake components including lines. There are many sites online that will have good brake bleeding information. www.classicperform.com, CPP's website is a good one.

Make sure you do a good job bleeding the master cylinder before you install it and bleed the brakes. I didn't do a good job and I have a spongy pedal. I need to take it off and try again. I used a Mighty-Vac at first to bleed the brakes but in the end I found it easier and quicker to have a buddy help me do it the old fashioned way.

65-72 chevytoys · 02-13-2007, 01:25 PM

Make sure you bench bleed the MC first. If you dont and try to bleed the lines it will take forever to get all the air out of the MC through the lines.

PanelDeland · 02-13-2007, 05:50 PM

You guy's use line wrenches? My wife confused the guy at Sears when she asked for them.He called them flare nut wrenches and had no idea there was another name or use for them.I hardly ever use a line wrench to bleed brakes.I can almost always get a box end wrench on the bleeders but have started using a socket most of the time.Sure keeps spraying fluid down and usually misses my safety glasses.

02-11-2007, 06:07 PM	#1
wakeboarddrumma Registered User Join Date: Apr 2006 Location: North alabama Posts: 111	Replacing Master Cylinder (Brakes) My brakes have been out for a while. So I haven't driven the truck. We called the shop we always take it to, and they said it's probably going to be the Master Cylinder. So we said ok, and then they were going to have to tow it, so we decided we'd replace it ourselves, as it couldn't be that hard. Anyways, we went to Advanced and got a rebuilt one yesterday, and I was just wondering how hard of a job it will be? How long am i looking at for the replacement?

02-11-2007, 07:10 PM	#2
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Replacing Master Cylinder (Brakes) Just follow the instructions for bench bleeding, then bleed all your brakes carefully and you should be done with an hour or maybe two or work in it. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-11-2007, 10:19 PM	#3
GMCBubba Registered User Join Date: Oct 2006 Location: Simpsonville, SC Posts: 255	Re: Replacing Master Cylinder (Brakes) yeah, i just finished mine a couple weeks ago. and if i can do it, then truly anyone can. __________________ 1969 GMC 3/4 ton, 307, 4-speed NP435GL, DANA 60, 4.10, HD rear leafs, manual everything, leaking oil and water. Now rocking 383, NV4500, power steering, power brakes. Finally undergoing restoration.

02-11-2007, 10:37 PM	#4
GMCBubba Registered User Join Date: Oct 2006 Location: Simpsonville, SC Posts: 255	Re: Replacing Master Cylinder (Brakes) oh, and if you're going to the effort to bleed your brake system, you might think about replacing your old brake hoses with new ones. mine were pretty bad. granted, i just replaced everything in my brake system except the hard lines. __________________ 1969 GMC 3/4 ton, 307, 4-speed NP435GL, DANA 60, 4.10, HD rear leafs, manual everything, leaking oil and water. Now rocking 383, NV4500, power steering, power brakes. Finally undergoing restoration.

02-11-2007, 10:40 PM	#5
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Replacing Master Cylinder (Brakes) buy a big jar of fluid as you will need it to bleed. takes two people as well... Might pick up a 7/16 line wrench if you don't have one. __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

02-11-2007, 11:13 PM	#6
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Replacing Master Cylinder (Brakes) Get a GOOD line wrench, don't cheap out here, you'll round off the nuts if you don't. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-12-2007, 07:40 AM	#8
GMCBubba Registered User Join Date: Oct 2006 Location: Simpsonville, SC Posts: 255	Re: Replacing Master Cylinder (Brakes) yes, rounded nuts. been there, done that. there's at least a couple good sides left to all of my nuts. but they're not as pretty as i would like. __________________ 1969 GMC 3/4 ton, 307, 4-speed NP435GL, DANA 60, 4.10, HD rear leafs, manual everything, leaking oil and water. Now rocking 383, NV4500, power steering, power brakes. Finally undergoing restoration.

02-12-2007, 09:13 PM	#9
wakeboarddrumma Registered User Join Date: Apr 2006 Location: North alabama Posts: 111	Re: Replacing Master Cylinder (Brakes) Well my older brother got the cylinder mounted. Said something about taking off the valves at the wheels and how he couldn't do it. This sound familiar? He stopped, and is going to finish up when he figures it out.

02-12-2007, 10:08 PM	#10
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Replacing Master Cylinder (Brakes) If the wheel cylinders are leaking then they need replaced, maybe the valves on them are bad, you have to open them to bleed the system __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

02-12-2007, 10:15 PM	#11
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Replacing Master Cylinder (Brakes) Here's a tip for those of us with cheap line wrenches. If there is room, clamp a pair of vice grips on the wrench to keep the ends from spreading, I figured that out in the junkyard the other day. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-12-2007, 10:54 PM	#13
wakeboarddrumma Registered User Join Date: Apr 2006 Location: North alabama Posts: 111	Re: Replacing Master Cylinder (Brakes) Is there a speacial tool for the front valves?

02-12-2007, 11:07 PM	#14
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Replacing Master Cylinder (Brakes) If you're talking about the bleeders, just use a boxed end wrench. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-13-2007, 08:05 AM	#15
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Replacing Master Cylinder (Brakes) It just struck me the other day in the junkyard. I had a pair of vicegrips in my hand and waalaah (or however you spell it). __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-13-2007, 12:01 PM	#17
JustLiveIt Registered User Join Date: Nov 2005 Location: Los Angeles, Ca Posts: 135	Re: Replacing Master Cylinder (Brakes) I just replaced my master cylinder and all brake components including lines. There are many sites online that will have good brake bleeding information. www.classicperform.com, CPP's website is a good one. Make sure you do a good job bleeding the master cylinder before you install it and bleed the brakes. I didn't do a good job and I have a spongy pedal. I need to take it off and try again. I used a Mighty-Vac at first to bleed the brakes but in the end I found it easier and quicker to have a buddy help me do it the old fashioned way. __________________ 1968 Chev SWB Fleet with GMC Clip and lots of 71-72 parts!

02-13-2007, 01:25 PM	#18
65-72 chevytoys Registered User Join Date: Dec 2006 Location: Wesley Chapel, Florida Posts: 1,113	Re: Replacing Master Cylinder (Brakes) Make sure you bench bleed the MC first. If you dont and try to bleed the lines it will take forever to get all the air out of the MC through the lines. __________________ 2004 Chevy Silverado 1500LS SWB 5.3L 2004 Corvette Z16 #770 Wish I had not sold 72 blazer



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02-13-2007, 05:50 PM	#19
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: Replacing Master Cylinder (Brakes) You guy's use line wrenches? My wife confused the guy at Sears when she asked for them.He called them flare nut wrenches and had no idea there was another name or use for them.I hardly ever use a line wrench to bleed brakes.I can almost always get a box end wrench on the bleeders but have started using a socket most of the time.Sure keeps spraying fluid down and usually misses my safety glasses. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

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