A356 Pump Housing Leak-Test Failures: RFQ Guide

# Pressure-Tight A356 Pump Housing RFQ Guide

When a pump housing fails a leak test, the next RFQ should not be a simple resend of the drawing and annual volume. The buyer needs a supplier to understand where the housing leaks, which cavities are pressure-bearing, which faces are machined, which datums control sealing alignment, and what evidence is available from the failed program.

This guide is written for sourcing managers, pump engineers, supplier quality engineers, and manufacturing teams preparing a pressure-tight A356 pump housing RFQ after leakage, porosity, machining, or second-source pressure. It complements Bohua's A356-T6 pump housing leak test RFQ checklist by focusing on what to send when the current supply path has already shown risk.

For connected Bohua routes, review the pump housing manufacturer page, leak-tight aluminum casting hub, quality control overview, and formal RFQ form.

Why this topic is high-intent

Searches around pressure-tight pump housings are usually not early education searches. A buyer who types leak test failure, pressure-tight A356 pump housing, or pump housing second source often has a drawing, a test requirement, and a reason to look beyond the current supplier.

Public supplier pages in the pump and valve casting space commonly emphasize pressure-tight parts, leak-free manufacturing, machined sealing features, and RFQ support. That is a useful market signal: for fluid-system buyers, the decision is not only casting price. It is whether the supplier can quote the full risk package around porosity, machining, sealing, testing, and records.

Do not hide the failure evidence

If the project is a second-source or recovery RFQ, the fastest path is to show the evidence. Buyers sometimes remove failure details because they worry a new supplier will price defensively. In practice, missing details often create a worse quote because every supplier makes different assumptions.

Send:

• •leak-test method, pressure, hold time, and pass/fail criterion
• •failed sample photos or marked drawings
• •whether the leak was through-wall, through a machined face, through a plug, through a threaded port, or through an assembly interface
• •CT, X-ray, section, dye-penetrant, or bubble-test evidence if available
• •whether leakage appeared before machining, after machining, after impregnation, after assembly, or after endurance testing
• •current alloy, heat treatment, and casting process if known
• •current machining sequence and sealing-face stock allowance

If the current supplier has not shared root-cause evidence, say that clearly. The new supplier can still review the drawing, but the quote should identify unknowns.

Map every sealed cavity before asking for price

For pressure-tight pump housings, a drawing may show the outer shape but still leave the quote unclear. Mark the sealed cavities and functional boundaries:

If the pump housing has multiple cavities, do not assume one test covers all of them. Ask whether each cavity needs a separate fixture, separate pressure stage, or isolated test path.

Define the leak test like a purchasing specification

The phrase leak test required is not enough for quote comparison. A serious RFQ should define the test in a way that purchasing, engineering, and SQE can all compare.

Include:

• •test medium: air, water, water-glycol, oil, helium, or customer-specific fluid
• •test pressure and hold time
• •allowable leak rate or visible leakage criterion
• •temperature if it affects the result
• •whether testing is 100 percent, sampling, first-article only, or production-lot based
• •whether the test happens before machining, after machining, after coating, after assembly, or at multiple stages
• •required record format: lot record, serial record, FAI/PPAP evidence, or customer form

If the buyer does not know the correct leak criterion, share the application pressure and fluid. The supplier can then ask the right engineering questions before tooling quote.

Link porosity control to machining datums

Pump housing leakage often appears after machining because cutting exposes sub-surface porosity near sealing faces, ports, or threaded features. That is why the RFQ should connect porosity-risk zones to machining datums.

Mark:

• •primary machining datum
• •sealing-face datum
• •critical bore datum
• •thread and port datum
• •minimum stock allowance on sealed faces
• •areas where X-ray, CT, or section control is required
• •areas where vacuum impregnation is prohibited, allowed, repair-only, or buyer-approval required

For pressure-tight A356 housings, the supplier should be able to explain how gating, risering, local wall balance, heat treatment, machining sequence, and inspection plan work together. A quote that treats casting and CNC as separate black boxes is weak for this kind of program.

Ask for a second-source comparison table

When the RFQ is a second-source project, ask the supplier to return a short comparison table with the quote:

This turns the quote into an engineering conversation rather than only a unit-price contest.

What to send Bohua for review

For a pressure-tight A356 pump housing RFQ, send:

• •2D PDF drawing and STEP model
• •marked sealed cavities and leak-test boundary
• •leak-test pressure, medium, hold time, and record expectation
• •current failure evidence if this is a recovery or second-source project
• •annual volume, sample quantity, and launch timing
• •alloy and heat-treatment requirement
• •machining datums, sealing faces, O-ring grooves, ports, and threads
• •inspection needs such as CMM, material certificate, X-ray/CT, FAI, PPAP, and traceability
• •whether vacuum impregnation is allowed, prohibited, or requires buyer approval

Use the formal RFQ form when the drawing pack is ready. For NDA-first recovery projects, start from the contact page.

Sources used for this RFQ guide

• •LeClaire Manufacturing pump and valve casting overview
• •Bohua pump housing manufacturer route
• •Bohua leak-tight aluminum casting hub
• •Bohua vacuum impregnation RFQ policy guide

Bottom line

A pressure-tight pump housing RFQ is strongest when it gives the supplier the drawing, the leak boundary, the failure evidence, the machining datums, the test method, and the record expectations in one package.

If the goal is to qualify a second source, do not only ask for a cheaper casting. Ask for a clearer pressure-tight manufacturing plan. Submit the pump housing RFQ package when the sealed-cavity map and leak-test target are ready.