Description

Tecbrake T675A, T465A Installation Manual – Factory OEM Specs for Mack Engines

If you’re bolting a Tecbrake T675A, T465A Installation Manual onto a Mack ENDT-673, 675, 676, or E6 six-cylinder two-valve head engine, you need the exact installation sequence. I’ve seen guys skip the intercooler adapter check and end up with a bent housing. This 15-page installation manual from Tecbrake is the factory document – not some third-party rewrite. It tells you which kit to use (TB960006 or TB960007) based on your intercooler setup, and gives you the torque values straight from the engineer’s desk. Page 2 lists the numbers: rocker bracket hold-down bolts at 35 lb-ft, slave piston adjuster screw nuts at 20 lb-ft. That’s the difference between a brake that works and one that leaks oil down the valve cover.

Section 1: Introduction and Kit Selection

The manual opens with a clear notice: the Tecbrake engine brake is a slowing device, not a substitute for service brakes. That’s not a suggestion – it’s a legal and safety boundary. Then it walks you through the two complete kit versions. If your Mack has an engine-mounted intercooler, you need kit TB960006 with the air-to-air adapter group. If it’s chassis-mounted, go with TB960007. The manual also warns about a Robert Bosch fuel pump requiring an optional switch bracket and actuating arm, and a turbocharged-but-not-intercooled engine needing a turbocharger spacer group. Every variation is covered.

Don’t skip the part about the longer turbo lube oil feed line. Mack part number 42QEA4451RB-32 is listed right there. Order it before you start.

Which Torque Values Are Critical?

Page 2 of the installation manual gives you five torque values that you cannot guess. Rocker bracket hold-down bolts: 35 lb-ft. Engine brake hold-down bolts: 35 lb-ft. Rocker arm adjuster screw nuts: 26 lb-ft. Slave piston adjuster screw nuts: 20 lb-ft. Fuel pump switch mounting bracket bolts: 100 lb-in. Use a calibrated torque wrench. I’ve pulled apart jobs where someone used a generic spec and snapped a bolt inside the head. These numbers are specific to the Tecbrake housing and the Mack rocker geometry.

Engine Preparation – What the Manual Covers

Section 2, Engine Preparation, starts on page 2. Clean the engine thoroughly before you remove anything. Then pull the valve covers and rocker arm assembly. The manual shows you Figure 2-1 and 2-2 for reference. Important note: older model Mack rocker levers may interfere with the engine brake housing because of the height at the valve pad end. The manual tells you to carefully remove a slight amount of material if needed – but it doesn’t specify how much. That calls for experience and a steady hand. If you’re a home garage guy, measure twice.

Get the right tool.

3 Special Tools You’ll Need

The manual lists exactly three special tools: a 9/16-inch crowfoot wrench, a 0.030-inch (0.76 mm) feeler gauge, and a torque wrench that reads foot-pounds and inch-pounds. The feeler gauge is critical for setting the slave piston adjustment. Without it, you’ll either have no braking effect or a valve that stays open. The crowfoot wrench gets you onto the rocker bracket bolts that are buried under the housing. Don’t substitute a regular wrench – you’ll strip the hex.

Avoid Common Installation Mistakes

Three mistakes I see again and again: using the wrong kit for the intercooler type, forgetting the fuel pump switch bracket on Bosch-equipped engines, and reusing the stock lube oil feed line when the turbo is repositioned. The manual addresses all three. It also reminds you that the engine brake is not a parking brake. You still need functional service brakes. Follow the order of operations in Section 2 – clean, disassemble, inspect, then install. Don’t reverse the steps.

Audience Fit: Who Needs This Manual

This 15-page document is for anyone who owns, maintains, or repairs a Mack truck with a 6-cylinder two-valve head. DIY mechanics working on their own rig will find the torque values and tool list essential. Shop owners: hand this to a junior tech and watch them finish the job without calling you for a spec. Real-world example: a fleet operator swapping an engine brake on a 1980s Mack dump truck – without the manual they’d be guessing which adapter group fits. Here, the answer is printed.

Source Validity – OEM vs. Aftermarket

This is the original Tecbrake factory installation manual – the same one that came in the box with the kit. Aftermarket reprints often omit the intercooler variation notes or change the part numbers. This PDF is a direct scan of the 15-page document, including all figures and the torque table. No third-party rewriting. If you’ve ever tried to install a Jake brake with a generic instruction sheet, you know why the OEM version matters. The part numbers, torque values, and warnings are exactly as Tecbrake released them.

Does this manual cover both the T675A and T465A models?

Yes, it covers both models for Mack 6-cylinder two-valve head engines.

What if my Mack engine has a chassis-mounted intercooler?

Then you need the TB960007 kit. The manual explains that the chassis-mounted intercooler does not require the air-to-air adapter group. However, you may need a longer turbocharger lube oil feed line – the manual gives the Mack part number 42QEA4451RB-32. If you skip this step and use the stock line, it may be too short, causing binding or leaks. Also, if you have a Robert Bosch fuel pump, the manual tells you to order an optional fuel pump switch bracket and actuating arm. The torque specs for the fuel pump switch mounting bracket bolts are 100 lb-in. This level of detail is why you want the factory manual.

If you’re also working on other equipment, check Drogobych Crane КТА-16, КТА-25, КТА-28 2004 Installation Manual or HYUNDAI SEASALL D170 & D150 Series Engines Installation Manual and Hella LEDay Flex Mounting Instructions. For background on manual transmissions, see Manual Transmission and Manual Transmission. Access the Factory Manual and keep it on your tablet next to the engine.