Description

Bentley Mark V 1947 Service Manual

If you’re working on a Bentley Mark V 1947 Service Manual—that’s the actual manual, not a reprint—you’ve got the same 87 pages I’d want on my bench. I’m Mike Callahan. This bulletin set covers the factory-issued service bulletins for the Mark V, including modifications and tappet replacement procedures that the dealerships got in ’47. No guesswork. Factory specs.

Period. That’s the difference between getting it right the first time and chasing oil leaks from a lost filler cap washer.

Bentley Mark V 1947 Service Manual: What the Bulletins Cover

You’re looking at two critical bulletins. Service Bulletin BB-7 addresses the engine oil filler cap washer—specifically, the fix for washers that kept falling off in service. The factory procedure: clean both surfaces, apply Postik No.772 adhesive, and press the rubber washer in permanently. That’s on page 1.

Bulletin BB-43 (supersedes BB-43 dated 1.54) covers replacement of tappets with the two‑window type. The old four‑window tappets needed a different clearance. The new ones are more rigid and heavier, so the fitting procedure changed. You’ll find the full color‑coding chart on page 2.

Engine Oil Filler Cap Washer Modification

Loss of that washer meant oil spraying under the hood and potential contamination. The manual tells you to verify if a car has been modified—if the washer lifts out easily, it’s not glued. Retailers were instructed to apply the fix and notify the Service Depot. For a home garage, just do it per the manual and note it in your log.

Tappet Replacement and Clearance Change

The two‑window tappet is color‑coded in steps of 0.00025″. Blue, green, yellow, black, black‑and‑yellow, green‑and‑yellow—no separate part numbers. You fit one size smaller than the old ‘feel fit’ method to avoid the tappet sticking when oil is cold. The noise is like slack pistons, not wear. The manual calls for a set of six of the latest tappets for gauging; use up older stock on repairs. That level of detail saves hours of diagnosising valve gear noise.

3 Reasons to Trust This Factory Documentation

First: it’s the actual OEM bulletin from 1947, not a third‑party summary. Second: the color code table is printed in the manual—no guessing which tappet diameter matches each color. Third: the superseded bulletin note warns you to destroy the old BB-43 to avoid confusion. Aftermarket reprints never include that.

Can This Manual Help with Post‑Delivery Adjustments?

Absolutely. The Mark V left the factory with a certain setup, but some cars were delivered before the oil cap modification took place. If you’re restoring a car that’s been sitting, you need to check the washer. Same with tappets—if a previous owner swapped in the wrong size, this manual gives you the corrective procedure. It’s a living document, not a static book.

Get the Correct Fitting Procedure for Two‑Window Tappets

The manual doesn’t just say “fit smaller.” It walks you through measuring the tappet bore, selecting the color code by diameter, and checking clearance when the engine is cold. It also warns that the earlier four‑window tappets should not be used as gauges because of color code changes. Skip that step and you’ll be chasing clatter for weeks.

Related manuals for other Bentleys include Bentley Mark VI 1947 Service Manual and Bentley MARK VI Service Manual Car Heater System and Bentley Mark VI 1949 Service Bulletin. For broader context on automotive documentation standards, see Automotive Industry Overview and Automotive Industry Overview.

What models does this manual cover?

Only the Bentley Mark V from 1947.

How do I apply the oil filler cap washer modification?

Find Service Bulletin BB-7 on page 1. Clean the cap recess and the rubber washer thoroughly with a solvent to remove any oil. Apply Postik No.772 adhesive to both surfaces, press the washer into place, and let it cure for at least 24 hours before adding oil. This prevents the washer from falling off during driving. The bulletin also states you should inform the Service Depot if you perform the modification, but for a home garage just note it in your logbook. That’s the factory procedure.

That’s the kind of detail you get here. If you want to work on a 1947 Bentley Mark V without making a 70‑year‑old mistake, you need the original factory documentation. Access the Factory Manual and get the exact same sheets the dealerships used.