The Stovebolt Page Forums Home | FAQ | Forum | Swap Meet | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Helping out ...


EVENTS

Check in for status!

Jump over to the Events Forum, to post events -- new ones or the ones we have been enjoying for some time.
Look to see what's been cancelled or postponed.

Encourage one another!

Stovebolt Site Search
 
Old Truck Calendars
Months of truck photos!
Nothing like an old truck calendar

Stovebolt Calendars

Check for details!


Who's Online Now
14 members (Donsz, 49 3100, archburycontrol, Goach2, glenns towing, Greg_H), 189 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums50
Topics120,637
Posts967,012
Members43,723
Most Online1,229
Jan 21st, 2020
Image Posting Policy
Previous Thread
Next Thread
Print Thread
Slave Cylinder Doesn’t Fit Backing Plate
#1325948 Thu Sep 12 2019 10:53 PM
Joined: Feb 2019
Posts: 795
P
Phak1 Offline OP
Jack of all Trades, Master of None
During reassembly of the front brakes on my 52’Chevy 1/2 ton, my new wheel cylinders I ordered (AC Delco from RockAuto) are too wide to fit. When I removed the installed cylinders I noticed that both dust boots were damaged and leaking, thus the reason for ordering new ones. Looking at the old cylinders its apparent that they didn’t fit either. Although they were narrower than the new AC Delco, when installed the rubber boots are getting pinched by a bracket that is attached to the backing plate. I ordered cylinders for a 52’ Chevy half ton and judging by the old cylinders the PO also ordered the same.

The second picture shows how the old cylinder boot was being pinched by the backing plate bracket.

The third shows how wide the new AC Delco is. Note that it’s still not even close to being seated.

Now I suspect the backing plate or maybe the whole axle is not from a 52’.

Any help sorting out this issue will be greatly appreciated.

Attached Files
DC922063-B036-4C65-895B-ECD3D654DFFD.jpeg (119.11 KB, 116 downloads)
EBEADE84-0A4E-44A9-8435-36E5EFA3E9AF.jpeg (153.95 KB, 118 downloads)
FD566035-5A06-459A-AAF9-E373227E519C.jpeg (125.41 KB, 116 downloads)
Last edited by Phak1; Fri Sep 13 2019 12:52 AM.

Phil

1952 Chevrolet 3100
Project Journals
‘59 235 & hydraulic lifters
“Three on the Tree” & 4:11 torque tube
12v w/ Alternator
Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1325971 Fri Sep 13 2019 01:38 AM
Joined: Mar 2010
Posts: 9,412
5
Master Gabster
As far as I know, that is how they are supposed to be. Every one that I have worked on were like that. Those rubber parts are not seals to keep fluid in. They are dust covers to keep dirt out. BTW, the Factory Repair Manual states that it is normal to find a small amount of brake fluid on the inside of those rubber parts. If it pours out when you peel them back for inspection, then you need to replace them.

Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1325975 Fri Sep 13 2019 02:05 AM
Joined: Feb 2019
Posts: 795
P
Phak1 Offline OP
Jack of all Trades, Master of None
The old cylinders can be installed by slightly depressing the boots. The reason I questioned if its correct, is because the removed cylinders had holes in both dust boots and were weeping where the damage was. This damage is consistent on both sides.
The new AC Delco slave cylinders are just way too big to fit so they are not made for this backing plate.


Phil

1952 Chevrolet 3100
Project Journals
‘59 235 & hydraulic lifters
“Three on the Tree” & 4:11 torque tube
12v w/ Alternator
Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1325994 Fri Sep 13 2019 05:45 AM
Joined: Mar 2010
Posts: 9,412
5
Master Gabster
Do the cylinders have a casting number on them? Someone on here may be able find out if they sold you the wrong parts.

Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1326008 Fri Sep 13 2019 11:52 AM
Joined: Feb 2019
Posts: 795
P
Phak1 Offline OP
Jack of all Trades, Master of None
I looked at the new AC Delco cylinders again and discovered that all I needed to do was to compress the boots and cylinders to get them to fit in between the bracket. If your saying that all of the cylinders you’ve installed look like that, they are probably correct.

I’m still wonder why the removed cylinder boots were cut by the bracket. I wonder if a PO pressed on the pedal when the drum was not installed crushing the boots between the pistons and the bracket. Another possibility is the pins that press against the shoes have been replaced and are too short.

Thanks 52CARL for your help.


Phil

1952 Chevrolet 3100
Project Journals
‘59 235 & hydraulic lifters
“Three on the Tree” & 4:11 torque tube
12v w/ Alternator
Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1326046 Fri Sep 13 2019 04:55 PM
Joined: Feb 2004
Posts: 20,890
H
Boltergeist
If you're concerned about the interference, just take an angle grinder to the bracket and widen the space a little. That bracket is only there to prevent the pistons from exiting the cylinder in case somebody has a stupid attack and doesn't adjust their brakes regularly. Some brake systems don't have them at all.
Jerry


The murder victim was drowned in a bathtub full of Rice Krispies and milk.
The coroner blamed the crime on a cereal killer!

Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1326067 Fri Sep 13 2019 08:51 PM
Joined: Feb 2019
Posts: 795
P
Phak1 Offline OP
Jack of all Trades, Master of None
No need the cut the brackets. I just finished installing the wheel cylinders and the brake shoes. Once I understood how they actually are installed, all went well.

My concern was the how the old boots got cut. I didn’t want to install new cylinders and have the same thing happen.

I try to be very through reassembling so I don’t have to do it again. I have found some pretty shoddy work on this truck so I am suspect of everything.

Thanks again Jerry and 52CARL for your support.


Phil

1952 Chevrolet 3100
Project Journals
‘59 235 & hydraulic lifters
“Three on the Tree” & 4:11 torque tube
12v w/ Alternator
Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1326077 Fri Sep 13 2019 10:54 PM
Joined: May 2005
Posts: 7,401
B
General Purpose
The rubber got cut due to many years of vibration. The sharp corner and edges of the stamped keeper can be "softened" with a file. Chinese "rubber" will last much less time.


Watch out for careful drivers!!!
I'm away on an ego trip. Will be back on Feb 30.
I'm not an Auto Mechanic, but I play one on TV.
I charge $0.02 for every opinion and I take Paypal.
Plan B is always better than plan A, by definition.


Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1326081 Fri Sep 13 2019 11:26 PM
Joined: Feb 2019
Posts: 795
P
Phak1 Offline OP
Jack of all Trades, Master of None
Good suggestion! Thanks! Unfortunately, they are already installed.


Phil

1952 Chevrolet 3100
Project Journals
‘59 235 & hydraulic lifters
“Three on the Tree” & 4:11 torque tube
12v w/ Alternator
Re: Slave Cylinder Doesn’t Fit Backing Plate
Phak1 #1326116 Sat Sep 14 2019 02:33 AM
Joined: Mar 2010
Posts: 9,412
5
Master Gabster
Sleep tight at night. If they get cut over time, nothing bad will happen. They are just dust caps. The cuts will be on the sides. If the pistons leak enough to ever reach as high as the cuts, the cylinders have gone bad and will need to come off anyway.


Moderated by  SWEET 

Link Copied to Clipboard
Home | FAQ | Forum | Swap Meet | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Powered by UBB.threads™ PHP Forum Software 7.7.4