Vickers 20VQ Single Vane Pump: Parts Catalog, Service Data & Rebuild Guide

Vickers 20VQ Vane Pump: Parts Catalog, Service Data & Rebuild Guide

The Vickers 20VQ is the high performance version of the 20V fixed displacement balanced vane pump. The VQ cartridge uses a flex-side plate and a 10 vane rotor, and the whole wearing assembly is replaced as one matched kit. Eaton documents the 20VQ cartridge inside the 2520VQ and 2521VQ service data, where it forms the cover end section, so the cartridge tables on this page carry those model prefixes. RestoPower supplies OEM or aftermarket equivalent cartridge kits, vane kits, rings, rotors, covers, relief valves and seal kits for every 20VQ build.

Exploded View and Parts Diagram

Vickers 20VQ vane pump exploded view diagram with cartridge kit table, cover sub-assembly table, relief valve settings and bolt torque values

Vickers 20VQ cartridge and cover assembly as documented in the 2520VQ service data. Every part number and torque figure quoted on this page is read directly off this drawing.

20VQ Cartridge Kits

Everything left of the cartridge kit column is included in the cartridge kit. Order the kit, not the individual pieces.

Model Rotor Vane Kit Ring Inlet Support Plate Cartridge Kit F3 Cartridge Kit
2*20*** 5** 402690 922741 333624 419502 417053 421588
2*20*** 8** 402690 922741 333625 419502 417054 421589
2*20*** 9** 402690 922741 374799 419502 423096 423097
2*20***11* 403539 922743 333626 419501 416427 421590
2*20***12* 403539 922743 353901 419501 416428 421591
2*20***14* 403539 922743 353902 419501 416429 421592
2*21*** 5** 428698 922741 333624 419502 428700 428707
2*21*** 8** 428698 922741 333625 419502 428701 428708
2*21*** 9** 428698 922741 374799 419502 428702 428709
2*21***11** 428699 922743 333626 419501 428703 428710
2*21***12** 428699 922743 353901 419501 428704 428711
2*21***14** 428699 922743 353902 419501 428705 428712

The 2*21 rows are the VQ replacement cartridges for the 2521 series. Vane kits contain 10 vanes and 10 inserts. Common cartridge parts across every row: outlet support plate 419500, seal pack 433762 S/A (4 req'd), flex-side plate kit 923955, back-up ring 588506, O-rings 154026 and 154090, seal ring 419672, pin 422206 (2 req'd), screw 416426 (2 req'd).

Cover Sub-Assembly by Cover Type

Model Cover Type Cover S/A
252*VQ*A/F*-****20 4-Bolt 250824
252*VQ*C/E*-****20 Straight Thread 252504
252*VQ*C/E*-**2*20 Flow Control 257560
252*VQ*C/E*-**4*20 Flow Control 257561
252*VQ*C/E*-**6*20 Flow Control 257562
252*VQ*C/E*-**7*20 Flow Control 257563
252*VQ*C/E*-**8*20 Flow Control 257564
252*VQ*C/E*-**10*20 Flow Control 257565
252*VQ*C/E*-**12*20 Flow Control 257999

Integral Relief Valve by Setting

Model Code Relief Valve Setting (PSI) Relief Valve S/A
C20 750 232794
D20 1000 232795
E20 1250 232796
F20 1500 232797
G20 1750 232798
H20 2000 232799
J20 2250 233019
K20 2500 233020

Relief valve is available on 20VQ models only, and not for the 12 and 14 ring sizes. Valve detail parts: plug 7077, snap ring 155023, spring 239766. Install the relief valve into the cover before installing the cartridge kit.

Vickers 20VQ Torque and Assembly Specs

Item Value
38523 Bolt (4 req'd) Oil the threads, then torque to 65-75 lb.ft
1296 Bolt (4 req'd) Oil the threads, then torque to 40-50 lb.ft
416426 Cartridge screw (2 req'd) 30 ± 5 lb.in
Vane count 10 vanes and 10 inserts
Housing (inlet) 251263

Bronze faces must be installed toward the rotor. This applies to the flex-side plate and the support plates, and it is the single most commonly missed instruction on a VQ cartridge.

Download the Service Data PDFs

How to Rebuild a Vickers 20VQ Vane Pump

A 20VQ rebuild is a cartridge job. The wearing parts, cam ring, rotor, vanes, flex-side plate and support plates, come as a matched cartridge kit, and the correct repair is to replace that kit rather than individual pieces. Budget two to three hours.

Step 1: Clean and Drain

Wash the outside of the pump before anything comes apart and drain the remaining oil. Grit left on the housing will find its way into the new cartridge. Read the drained oil: bronze glitter points to the cartridge or bearing, steel points to the shaft or rotor.

Step 2: Mark Orientation and Remove the Cover

Scribe the cover to housing relationship and the port positions before undoing anything. Note your cover type, because a flow control or straight thread cover is a different sub-assembly from a plain 4-bolt cover. Remove the four 1296 bolts evenly in a crossing pattern and lift the cover straight off.

Step 3: Withdraw the Cartridge Kit

Lift out the cartridge as an assembly: inlet support plate, cam ring, rotor with its 10 vanes and inserts, flex-side plate and outlet support plate 419500. Note which face of the cam ring pointed toward the cover, because the ring is directional. The two 422206 pins locate the cartridge; check they have not stayed in the cover.

Step 4: Relief Valve, Shaft, Bearing and Seal

If your pump has an integral relief valve, remove it from the cover and note its setting code, since the valve sub-assembly is selected by pressure setting from the table above. Then remove the retaining ring and press the shaft out from the drive end, and inspect the shaft seal running surface for a wear groove. A grooved shaft will leak straight through a new seal.

Step 5: Inspect and Decide

  • Cam ring: look for a wear step at the two lift zones. Any ridge you can feel with a fingernail condemns the whole cartridge kit.
  • Rotor slots: check for bell mouthing at the outer edge, which lets the vanes cock and chatter.
  • Vanes and inserts: chipped or rounded leading edges mean the pump has been running cavitated. Fix the inlet or it will happen again. Vane kit 922741 or 922743 covers all 10.
  • Flex-side plate and support plates: scoring or bronze pickup on the running faces condemns them. Flex-side plate kit 923955 is the service part.
  • Relief valve: a valve that will not hold its setting is usually a tired 239766 spring or a scored poppet seat.

Step 6: Reassemble and Torque

  • Fit a complete new cartridge kit for your model code from the table above. Never mix a new cam ring with old vanes; they wear as a matched set.
  • Install the bronze faces toward the rotor, on both the flex-side plate and the support plates.
  • Install the relief valve into the cover before the cartridge kit goes in. Doing it afterwards means taking the pump apart again.
  • Fit all new seals, including back-up ring 588506, seal ring 419672 and O-rings 154026 and 154090, lubricated with clean hydraulic oil rather than grease.
  • Confirm the two 422206 locating pins are seated, and torque the two 416426 cartridge screws to 30 ± 5 lb.in.
  • Prefill the housing with clean oil, then oil the threads and torque the four 38523 bolts to 65-75 lb.ft and the four 1296 bolts to 40-50 lb.ft, both evenly in a crossing pattern.

Step 7: Test and Run In

Turn the shaft by hand; it should rotate smoothly with no tight spots. Start the machine unloaded at low speed, bleed the circuit, and confirm the pump primes within a few seconds. Run unloaded for several minutes before applying pressure. If an integral relief valve is fitted, verify it cracks at its rated setting before returning the machine to work.

Common 20VQ Faults and the Parts That Fix Them

  • Whining or chattering under load: worn cam ring and vanes, or a restricted inlet. Check the inlet first.
  • Oil weeping at the shaft: worn shaft seal, or a grooved shaft if the leak returns quickly.
  • Low flow at rated speed: worn cartridge kit.
  • System pressure capped below normal: integral relief valve set low or spring 239766 tired. Check the setting code against the table.
  • Rapid cartridge failure after rebuild: a bronze face installed away from the rotor.
  • Pump will not prime: air leak on the suction side, or vanes stuck in the rotor slots.

Vickers 20VQ Specifications

  • Type: Fixed displacement balanced vane pump, high performance VQ cartridge
  • Vanes: 10 vanes and 10 inserts per cartridge
  • Cover types: 4-bolt, straight thread, and flow control
  • Optional integral relief valve: 750 to 2500 PSI, not available on 12 and 14 ring sizes
  • 38523 bolt torque: 65-75 lb.ft, threads oiled
  • 1296 bolt torque: 40-50 lb.ft, threads oiled
  • Cartridge screw torque: 30 ± 5 lb.in
  • Compatible brands: Vickers, Eaton Vickers, Danfoss legacy
  • Applications: Machine tools, industrial presses, injection molding, mobile hydraulics

Shop OEM or Aftermarket Equivalent 20VQ Replacement Parts

Frequently Asked Questions

How do you rebuild a Vickers 20VQ vane pump?

Drain and clean the pump, scribe the cover orientation, remove the four 1296 bolts and withdraw the cartridge kit, remove the relief valve from the cover if one is fitted, replace the shaft seal and bearing, then fit a complete new cartridge kit with all bronze faces toward the rotor, install the relief valve into the cover before the cartridge goes back in, torque the two 416426 cartridge screws to 30 plus or minus 5 lb.in, then oil the threads and torque the 38523 bolts to 65-75 lb.ft and the 1296 bolts to 40-50 lb.ft.

What is the bolt torque on a Vickers 20VQ?

There are two figures, and the threads are oiled for both. The four 38523 bolts torque to 65 to 75 lb.ft and the four 1296 bolts torque to 40 to 50 lb.ft. The two 416426 cartridge screws are a much lower 30 plus or minus 5 lb.in.

What relief valve setting does my 20VQ have?

Read the letter code before the 20 suffix in your model number. C20 is 750 PSI (valve 232794) rising in 250 PSI steps to K20 at 2500 PSI (valve 233020). The integral relief valve is available on 20VQ models only, and not on the 12 and 14 ring sizes.

Which way round do the bronze faces go on a 20VQ cartridge?

Bronze faces must be installed toward the rotor, on both the flex-side plate and the support plates. Fitted the other way round the cartridge will fail quickly.

Why is the 20VQ cartridge listed under 2520VQ model numbers?

Because Eaton documents the 20VQ cartridge inside the 2520VQ service data, where the 20VQ forms the cover end section of the double pump. The cartridge kits are the same parts whether the section is fitted in a single 20VQ or as the cover end of a 2520VQ or 2521VQ.

Related Catalogs

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