Bleed Procedure for GM Concentric Slave Cylinder - Transmission Digest

Bleed Procedure for GM Concentric Slave Cylinder

If you have been installing clutches for a while, you are probably familiar with the dreaded Ford Ranger concentric slave cylinder and the difficulties and uncertainty presented when you’re attempting to bleed it. Unfortunately, General Motors has followed suit with similar concentric slave cylinders. Most General Motors vehicle designs do not provide access to the slave cylinder without separating the transmission from the engine. Additionally, some models do not have bleed ports.

Bleed Procedure for GM Concentric Slave Cylinder

Standard Issues

Author: Gabe Vajda
Subject Matter: Manual clutch
Vehicle Applications: General Motors
Issue: Bleeding slave cylinder

Standard Issues

  • Author: Gabe Vajda
  • Subject Matter: Manual clutch
  • Vehicle Applications: General Motors
  • Issue: Bleeding slave cylinder

If you have been installing clutches for a while, you are probably familiar with the dreaded Ford Ranger concentric slave cylinder and the difficulties and uncertainty presented when you’re attempting to bleed it.

Unfortunately, General Motors has followed suit with similar concentric slave cylinders. Most General Motors vehicle designs do not provide access to the slave cylinder without separating the transmission from the engine. Additionally, some models do not have bleed ports.

To assist with bleeding these problematic slaves, the following steps detail the proper procedure to bleed the system correctly while the transmission is off the vehicle.***

Step 1: Verify that the clutch master cylinder has a full fluid fill. If not, add additional fluid until full.

Step 2: Ensure that the clutch master cylinder is mounted level on the firewall. Some vehicles may require the master cylinder to be unbolted, leveled and reattached to the firewall.

Step 3: Install the concentric slave cylinder on the transmission. Note: Some slave cylinders have the input-shaft seal built in (Figure 1). This seal MUST be lubricated! Failure to lubricate will result in seal damage and leakage.

Step 4: Lift the transmission up into the vehicle but do not mount the transmission to the engine. With the transmission lifted, reach up and connect the hydraulic line to the slave cylinder.

Step 5: Once the slave and hydraulic line are connected, reach into the bellhousing and push the slave cylinder back in its bore (Figure 2), then release and let it return to its original position (Figure 3). Repeat this process 12–15 times. Following this procedure will force any air trapped in the hydraulic line back up through the master cylinder, through its vent cap and out of the system.

Bleed complete.

*** This procedure will work on ANY vehicle with a concentric slave cylinder. It is the ONLY way to bleed many newer applications that do not have bleeder valves.

Gabe Vajda, ASE certified technician, is a technical-support engineer for the LuK, FAG and INA product lines of Schaeffler Group USA Inc.

You May Also Like

Sometimes, a diagnostic code is all you need

With ATSG having the opportunity to help shops solve problems, sometimes we get faced with some real doozies. A shop will call and give us a laundry list of DTCs, leaving us to think someone must have a bulkhead connector unplugged. We then go through the arduous task of deciding which codes prompted other codes

With ATSG having the opportunity to help shops solve problems, sometimes we get faced with some real doozies. A shop will call and give us a laundry list of DTCs, leaving us to think someone must have a bulkhead connector unplugged. We then go through the arduous task of deciding which codes prompted other codes to set—we’re actually diagnosing diagnostic codes themselves at that point. So, when an issue comes up on our help line with codes that actually tell the story, it makes for a nice change, as well as a quick pathway to a repaired vehicle.

10L80 and 10R80 pump gear differences

You may have seen an article in the August 2023 issue of Transmission Digest called “GM 10L80: A new kind of pump noise,” which goes over how the front cover housing in the 10L80 is fitted with a converter drive gear and idler gear. The idler gear drives the pump’s driven gear, and is press

Shift Pointers: What to do when the 62TE TRS tab breaks

How frustrating it is when on a hot summer day, as you go to open a nice cold can of your drink of choice, and the tab breaks off? You are outside, away from any tools to remedy the problem quickly. It now requires a MacGyver mentality looking around at the resources available to get

Going the extra mile: Proving your transmission repair suspicions

A 2003 Honda Pilot with a five-speed three-shaft transmission came into our shop with a customer concern that the vehicle had no power, and the “D” light was flashing. I first did a scan for codes to see what it came up with, and the scan tool returned four DTCs: P1298 (ELD voltage high), P0135 (H02S

RRfeature-1400
Diagnosing Ford 10R60, 10R80 and 10R140 series speed sensor issues

Ford 10-speed 10R series transmissions utilize four two-wire, Hall-effect sensors — TSS, ISSA, ISSB and OSS — for providing speed signals to PCM or TCM. They are supplied nine volts by a PCM or TCM and assist in the control of clutch apply/release timing that is used in determining shift quality, including TCC. Related Articles

Other Posts

Shift Pointers: Failures caused by incorrect tire sizes

For years ATSG has produced a wide range of issues related to improper tire sizes on vehicles. Even under-inflated tires have been known to cause issues. Problems such as premature failure with an active 4WD transfer case will occur with incorrect tire sizes. Related Articles – Valve body and component suppliers: A comprehensive list –

Shift-Pointers-Jan-Figure-1-1400
Understanding lube flow control valves in Toyota/Lexus UA/UB80 transmissions

The Toyota/Lexus UA80 and UB80 transmissions first came out in 2017 in Highlanders and Siennas. The UA80 is used in V6 applications, and the UB80 is paired with four-cylinder versions. They have been called Toyota New Global Architecture type transmissions, and alternately referred to as the “Direct Shift 8AT” eight-speed automatic transmission. This transmission was

Tasc-Tip-December-Figure-1---LFC-Valve-OE-Partial-Circuit-Diagram-1400
How reading through service bulletins can turn a technician into the customer’s hero

Over the last 28 years of being a technician, I have developed the habit of checking for and reading technical service bulletins at the forefront of the diagnostic process, especially when an unfamiliar vehicle exhibiting blatant or straightforward concerns comes into the shop. I have found many valuable nuggets of information while reading over these

Sometimes, you should sweat the small stuff

It’s a common phrase: There may have been a time when you worried about something, and someone who knew what you are going through said, “Hey, don’t sweat the small stuff.” Sometimes, this may be good advice. But other times, it may be wise to handle the small stuff before it becomes bigger “stuff.”  Related