GP7145 and GP7255A Repair Instructions, To Check Valves

GP7145 and GP7255A Repair Instructions

TO CHECK VALVES

Loosen plugs (58), take out tension spring (57) and then remove the complete valve assembly (51) with either a valve tool or an M16 hexagon screw. To remove the valve adapter (56) and tension spring (57), use a pullout tool size 5. To disassemble valve assembly, carefully hit the top of the valve plate (51C) with a metal dowel and press the valve seat (51E) out of the valve adapter (56). Check sealing surfaces and replace worn parts. Check O-rings and support rings. Tighten plugs (58) to 107 ft.-lbs. (145 NM).

TO CHECK SEALSAND PLUNGER PIPE

Loosen nuts (49A) and remove pump head (50). Separate the plunger connection (36A) from the cross- head (25) by means of two open-end wrenches (size 22mm and 27mm). Pull seal sleeves (39) out of their fittings in the crankcase (1). Take the seal case (38) out of the seal sleeve (39). Examine the plunger parts (36A-36D), seals (42 & 39A) and O-rings (38A & 38B). When replacing the plunger pipe (36B), tighten tension screws (36C) to 30 ft. lbs. (40 NM). Replace worn parts; grease seals with Silicone before install- ing.

CAUTION: Don't loosen the 3 plunger connections (36A) before the valve casing has been removed otherwise the tension screw (36C) could hit against the valve adapter (56) when the pump is being turned. Seal life can be increased if the pre-tensioning allows for a little leakage. This assists lubrication and keeps the seals cool. It is therefore not necessary to replace seals before the leakage becomes too heavy and causes output and operating pressure to drop.

MOUNTING VALVE CASING

Check O-rings (38A & 38B) on the seal case (38). Clean surfaces of seal sleeves in gear box and sealing surfaces of valve casing (50). Push the valve casing carefully on the O-rings of the seal case and centering studs (50A). Tighten nuts (49A) to 103 ft. lbs. (140 NM).

TO DISASSEMBLE GEAR

Take out plunger (36) and seal sleeves (39) as described above. Drain the oil. After removing the circlip ring (33B), lever out seal retainer (33) with a screw driver. Check seals (32 & 33A) and surfaces of crosshead (25) . Remove the crankcase cover (4). Loosen inner hexagon screws on the connecting rods (24).

Note: Connecting rods are marked for identification. Do not twist connecting rod halves. Each connect- ing rod is to be reinstalled in the same position (and orientation) on the crankshaft journals.

Push the connecting rod halves as far into the crosshead guide as possible. Check the surfaces of connect- ing rod and crankshaft (22). Take out the bearing cover (14) to one side and push out crankshaft taking particular care that the connecting rod doesn’t bend.

Re-assemble in reverse order. Regulate axial bearing clearance to a minimum of 0.1mm and a maximum of 0.15mm by means of fitting discs (20A). The crankshaft should turn easily and with little clearance. Tighten screws (24) to 30 ft.-lbs. (40 NM).

Important! The connecting rod has to be able to slightly move sidewise at the crankshaft journal.

Important! Seal (32) must always be installed so that the seal-lip on the inside diameter faces the oil. Possible axial float of the seal retainer (33) should be compensated with the shims (33C).

GP7145 specifications

The Giant GP7145 is a high-performance bicycle that has captured the attention of cycling enthusiasts and professional riders alike. This model exemplifies innovation and quality in bike engineering, making it a standout in the competitive cycling market.

One of the primary features of the Giant GP7145 is its lightweight frame, constructed from advanced aluminum alloy. This material not only contributes to the bike's overall agility but also enhances durability and strength. Riders will appreciate the responsiveness and maneuverability that the lightweight design provides, especially during long rides or competitive events.

The GP7145 is equipped with an advanced suspension system, which includes a front fork with adjustable travel. This technology allows riders to customize their experience based on terrain and personal preference. Whether tackling rugged trails or cruising on smooth pavements, the suspension system provides optimal comfort and control, reducing fatigue during extended rides.

Another remarkable characteristic of the Giant GP7145 is its state-of-the-art gear system, featuring a high-precision, multi-speed drivetrain. This component ensures seamless shifting, allowing riders to tackle steep hills or accelerate quickly on flat roads with ease. The gear ratios are designed to cater to various riding styles, whether you are a casual rider or seeking to push your limits in competitive racing.

Braking performance is also a priority in the design of the GP7145. The bike comes with hydraulic disc brakes that offer phenomenal stopping power, enhancing safety and control in all conditions. This feature is particularly beneficial in wet or muddy environments, where reliable braking is crucial.

The GP7145 is designed with rider ergonomics in mind. The geometry of the frame allows for a comfortable riding position, reducing strain on the back and shoulders during long rides. Additionally, the bike features adjustable components such as the seat and handlebars, ensuring a perfect fit for riders of different heights and preferences.

Lastly, the aesthetic appeal of the Giant GP7145 cannot be overlooked. With a sleek design and vibrant colors, this bicycle not only performs exceptionally but also stands out visually. Overall, the Giant GP7145 encapsulates the perfect blend of technology, performance, and comfort, making it an excellent choice for a wide range of cyclists seeking quality and reliability in their rides.